Extracellular proteins play an important role in the formation, differentiation and maintenance of multicellular organisms. The fate of many individual cells, e.g., proliferation, migration, differentiation, or interaction with other cells, is typically governed by information received from other cells and/or the immediate environment. This information is often transmitted by secreted polypeptides (for instance, mitogenic factors, survival factors, cytotoxic factors, differentiation factors, neuropeptides, and hormones) which are, in turn, received and interpreted by diverse cell receptors or membrane-bound proteins. These secreted polypeptides or signaling molecules normally pass through the cellular secretory pathway to reach their site of action in the extracellular environment.
Secreted proteins have various industrial applications, including pharmaceuticals, diagnostics, biosensors and bioreactors. Most protein drugs available at present, such as thrombolytic agents, interferons, interleukius, erythropoietins, colony stimulating factors, aid various other cytokines, are secretory proteins. Their receptors, which are membrane proteins, also have potential as therapeutic or diagnostic agents. Efforts are being undertaken by both industry and academia to identify new, native secreted proteins. Many efforts are focused on the screening of mammalian recombinant DNA libraries to identify the coding sequences for novel secreted proteins. Examples of screening methods and techniques are described in the literature [see, for example, Klein et al., Proc. Natl. Acad. Sci., 93:7108–7113 (1996); U.S. Pat. No. 5,536,637)].
Membrane-bound proteins and receptors can play an important role in the formation, differentiation and maintenance of multicellular organisms. The fate of many individual cells, e.g., proliferation, migration, differentiation, or interaction with other cells, is typically governed by information received from other cells and/or the immediate environment. This information is often transmitted by secreted polypeptides (for instance, mitogenic factors, survival factors, cytotoxic factors, differentiation factors, neuropeptides, and hormones) which are, in turn, received and interpreted by diverse cell receptors or membrane-bound proteins. Such membrane-bound proteins and cell receptors include, but are not limited to, cytokine receptors, receptor kinases, receptor phosphatases, receptors involved in cell-cell interactions, and cellular adhesin molecules like selectins and integrins. For instance, transduction of signals that regulate cell growth and differentiation is regulated in part by phosphorylation of various cellular proteins. Protein tyrosine kinases, enzymes that catalyze that process, can also act as growth factor receptors. Examples include fibroblast growth factor receptor and nerve growth factor receptor.
Membrane-bound proteins and receptor molecules have various industrial applications, including as pharmaceutical and diagnostic agents. Receptor immunoadhesins, for instance, can be employed as therapeutic agents to block receptor-ligand interaction. The membrane-bound proteins can also be employed for screening of potential peptide or small molecule inhibitors of the relevant receptor/ligand interaction. Efforts are being undertaken by both industry and academia to identify new, native receptor proteins. Many efforts are focused on the screening of mammalian recombinant DNA libraries to identify the coding sequences for novel receptor proteins.
We herein describe the identification and characterization of novel secreted and transmembrane polypeptides and novel nucleic acids encoding those polypeptides.
1. PRO213
Human growth arrest-specific gene 6 (gas6) encodes a protein that is expressed in a variety of different tissues and which has been reported to be highly expressed during periods of serum starvation and negatively regulated during growth induction. See Manfioletti et al., Mol. Cell. Biol. 13(8):4976–4985 (1993) and Stitt et al., Cell 80:661–670 (1995). Manfioletti et al. (1993), supra, have suggested that the gas6 protein is member of the vitamin K-dependent family of proteins, wherein the members of the latter family of proteins (which include, for example, Protein S, Protein C and Factor X) all play regulatory roles in the blood coagulation pathway. Thus, it has been suggested that gas6 may play a role in the regulation of a protease cascade relevant in growth regulation or in the blood coagulation cascade.
Given the physiological importance of the gas6 protein, efforts are currently being undertaken by both industry and academia to identify new, native proteins which are homologous to gas6. Many of these efforts are focused on the screening of mammalian recombinant DNA libraries to identify the coding sequences for novel secreted and membrane-bound receptor proteins, specifically those having homology to gas6. Examples of such screening methods and techniques are described in the literature [see, for example, Klein et al., Proc. Natl. Acad. Sci., 93:7108–7113 (1996); U.S. Pat. No. 5,536,637)]. We herein describe the identification of a novel polypeptide which has homology to the gas6 polypeptide.
2. PRO274
The 7-transmembrane (“7TM”) proteins or receptors, also referred to in the literature as G-protein coupled receptors, are specialized proteins designed for recognition of ligands and the subsequent signal transduction of information contained within those ligands to the machinery of the cell. The primary purpose of cell surface receptors is to discriminate appropriate ligands from the various extracellular stimuli which each cell encounters, then to activate an effector system that produces an intracellular signal, thereby controlling cellular processes. [Dohlman, H., Ann. Rev. Biochem., 60:653 (1991)]. The ability of 7TM receptors to bind ligand to a recognition domain and allosterically transmit the information to an intracellular domain is a specialized feature of 7TM proteins [Kenakin, T., Pharmacol. Rev., 48:413 (1996)]. The gene family which encodes the 7TM receptors or G-protein linked receptors encode receptors which recognize a large number of ligands, including but not limited to, C5a, interleukin 8 and related chemokines. Research in this area suggests that distinct signals at the cell surface feed into common pathways of cell activation. [Gerard, C. and Gerard, N., Curr. Op. Immunol., 6:140 (1994), Gerard, C. and Gerard, N., Ann. Rev. Immunol., 12:775 (1994)]. The superfamily of 7TM or G-protein coupled receptors contains several hundred members able to recognize various messages such as photons, ions and amino acids among others [Schwartz, T. W., et al., H., Trends in Pharmacol. Sci., 17(6):213 (1996)]. [Dohlman, H., Ann. Rev. Biochem., 60:653 (1991)]. [Schwartz, T. W., et al., H., Eur. J. Pharm. Sci., 2:85 (1994)]. We describe herein the identification of a novel polypeptide (designated herein as PRO274) which has homology to the 7 transmembrane segment receptor proteins and the Fn54 protein.
3. PRO300
The Diff 33 protein is over-expressed in mouse testicular tumors. At present its role is unclear, however, it may play a role in cancer. Given the medical importance of understanding the physiology of cancer, efforts are currently being under taken to identify new, native proteins which are involved in cancer. We describe herein the identification of a novel polypeptide which has homology to Diff 33, designated herein as PRO300.
4. PRO284
Efforts are currently being undertaken to identify and characterize novel transmembrane proteins. We herein describe the identification and characterization of a novel transmembrane polypeptide, designated herein as PRO284.
5. PRO296
Cancerous cells often express numerous proteins that are not expressed in the corresponding normal cell type or are expressed at different levels than in the corresponding normal cell type. Many of these proteins are involved in inducing the transformation from a normal cell to a cancerous cell or in maintaining the cancer phenotype. As such, there is significant interest in identifying and characterizing proteins that are expressed in cancerous cells. We herein describe the identification and characterization of a novel polypeptide having homology to the sarcoma-amplified protein SAS, designated herein as PRO296.
6. PRO329
Immunoglobulin molecules play roles in many important mammalian physiological processes. The structure of immunoglobulin molecules has been extensively studied and it has been well documented that intact immunoglobulins possess distinct domains, one of which is the constant domain or Fc region of the immunoglobulin molecule. The Fc domain of an immunoglobulin, while not being directly involved in antigen recognition and binding, does mediate the ability of the immunoglobulin molecule, either uncomplexed or complexed with its respective antigen, to bind to Fc receptors either circulating in the serum or on the surface of cells. The ability of an Fc domain of an immunoglobulin to bind to an Fc receptor molecule results in a variety of important activities, including for example, in mounting an immune response against unwanted foreign particles. As such, there is substantial interest in identifying novel Fc receptor proteins and subunits thereof. We herein describe the identification and characterization of a novel polypeptide having homology to a high affinity immunoglobulin Fc receptor protein,, designated herein as PRO329.
7. PRO362
Colorectal carcinoma is a malignant neoplastic disease which has a high incidence in the Western world, particularly in the United States. Tumors of this type often metastasize through lymphatic and vascular channels and result in the death of some 62,000 persons in the United States annually.
Monoclonal antibody A33 (mAbA33) is a murine immunoglobulin that has undergone extensive preclinical analysis and localization studies in patients inflicted with colorectal carcinoma (Welt et al., J. Clin. Oncol. 8:1894–1906 (1990) and Welt et al., J. Clin. Oncol. 12:1561–1571 (1994)). mAbA33 has been shown to bind to an antigen found in and on the surface of normal colon cells and colon cancer cells. In carcinomas originating from the colonic mucosa, the A33 antigen is expressed homogeneously in more than 95% of the cases. The A33 antigen, however, has not been detecting in a wide range of other normal tissues, i.e., its expression appears to be rather organ specific. Therefore, the A33 antigen appears to play an important role in the induction of colorectal cancer.
Given the obvious importance of the A33 antigen in tumor cell formation and/or proliferation, there is substantial interest in identifying homologs of the A33 antigen. In this regard, we herein describe the identification and characterization of a novel polypeptide having homology to the A33 antigen protein, designated herein as PRO362.
8. PRO363
The cell surface protein HCAR is a membrane-bound protein that acts as a receptor for subgroup C of the adenoviruses and subgroup B of the coxsackieviruses. Thus, HCAR may provide a means for mediating viral infection of cells in that the presence of the HCAR receptor on the cellular surface provides a binding site for viral particles, thereby facilitating viral infection.
In light of the physiological importance of membrane-bound proteins and specifically those which serve a cell surface receptor for viruses, efforts are currently being undertaken by both industry and academia to identify new, native membrane-bound receptor proteins. Many of these efforts are focused on the screening of mammalian recombinant DNA libraries to identify the coding sequences for novel receptor proteins. We herein describe a novel membrane-bound polypeptide having homology to the cell surface protein HCAR and to various tumor antigens including A33 and carcinoembryonic antigen, designated herein as PRO363, wherein this polypeptide may be a novel cell surface virus receptor or tumor antigen.
9. PRO868
Control of cell numbers in mammals is believed to be determined, in part, by a balance between cell proliferation and cell death. One form of cell death, sometimes referred to as necrotic cell death, is typically characterized as a pathologic form of cell death resulting from some trauma or cellular injury. In contrast, there is another, “physiologic” form of cell death which usually proceeds in an orderly or controlled manner. This orderly or controlled form of cell death is often referred to as “apoptosis” [see, e.g., Barr et al., Bio/Technology, 12:487–493 (1994); Steller et al., Science, 267:1445–1449 (1995)]. Apoptotic cell death naturally occurs in many physiological processes, including embryonic development and clonal selection in the immune system [Itoh et al., Cell, 66:233–243 (1991)]. Decreased levels of apoptotic cell death have been associated with a variety of pathological conditions, including cancer, lupus, and herpes virus infection [Thompson, Science, 267:1456–1462 (1995)]. Increased levels of apoptotic cell death may be associated with a variety of other pathological conditions, including AIDS, Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, multiple sclerosis, retinitis pigmentosa, cerebellar degeneration, aplastic anemia, myocardial infarction, stroke, reperfusion injury, and toxin-induced liver disease [see, Thompson, supra].
Apoptotic cell death is typically accompanied by one or more characteristic morphological and biochemical changes in cells, such as condensation of cytoplasm, loss of plasma membrane microvilli, segmentation of the nucleus, degradation of chromosomal DNA or loss of mitochondrial function. A variety of extrinsic and intrinsic signals are believed to trigger or induce such morphological and biochemical cellular changes [Raff, Nature, 356:397–400 (1992); Steller, supra; Sachs et al., Blood, 82:15 (1993)]. For instance, they can be triggered by hormonal stimuli, such as glucocorticoid hormones for immature thymocytes, as well as withdrawal of certain growth factors [Watanabe-Fukunaga et al., Nature, 356:314–317 (1992)]. Also, some identified oncogenes such as myc, rel, and ElA, and tumor suppressors, like p53, have been reported to have a role in inducing apoptosis. Certain chemotherapy drugs and some forms of radiation have likewise been observed to have apoptosis-inducing activity [Thompson, supra].
Various molecules, such as tumor necrosis factor-α (“TNF-α”), tumor necrosis factor-β (“TNF-β” or “lymphotoxin-α”), lymphotoxin-β (“LT-β”), CD30 ligand, CD27 ligand, CD40 ligand, OX-40 ligand, 4-1BB ligand, Apo-1 ligand (also referred to as Fas ligand or CD95 ligand), and Apo-2 ligand (also referred to as TRAIL) have been identified as members of the tumor necrosis factor (“TNF”) family of cytokines [See, e.g., Gruss and Dower, Blood, 85:3378–3404 (1995); Pitti et al., J. Biol. Chem., 271:12687–12690 (1996); Wiley et al., Immunity, 3:673–682 (1995); Browning et al., Cell, 72:847–856 (1993); Armitage et al. Nature, 357:80–82 (1992), WO 97/01633 published Jan. 16, 1997; WO 97/25428 published Jul. 17, 1997]. Among these molecules, TNF-α, TNF-β, CD30 ligand, 4-1BB ligand, Apo-1 ligand, and Apo-2 ligand (TRAIL) have been reported to be involved in apoptotic cell death. Both TNF-α and TNF-β have been reported to induce apoptotic death in susceptible tumor cells [Schmid et al., Proc. Natl. Acad. Sci., 83:1881 (1986); Dealtry et al., Eur. J. Immunol., 17:689 (1987)]. Zheng et al. have reported that TNF-α is involved in post-stimulation apoptosis of CD8-positive T cells [Zheng et al., Nature, 377:348–351 (1995)]. Other investigators have reported that CD30 ligand may be involved in deletion of self-reactive T cells in the thymus [Amakawa et al., Cold Spring Harbor Laboratory Symposium on Programmed Cell Death, Abstr. No. 10, (1995)].
Mutations in the mouse Fas/Apo-1 receptor or ligand genes (called lpr and gld, respectively) have been associated with some autoimmune disorders, indicating that Apo-1 ligand may play a role in regulating the clonal deletion of self-reactive lymphocytes in the periphery [Krammer et al., Curr. Op. Immunol., 6:279–289 (1994); Nagata et al., Science, 267:1449–1456 (1995)]. Apo-1 ligand is also reported to induce post-stimulation apoptosis in CD4-positive T lymphocytes and in B lymphocytes, and may be involved in the elimination of activated lymphocytes when their function is no longer needed [Krammer et al., supra; Nagata et al., supra]. Agonist mouse monoclonal antibodies specifically binding to the Apo-1 receptor have been reported to exhibit cell killing activity that is comparable to or similar to that of TNF-α [Yonehara et al., J. Exp. Med., 169:1747–1756 (1989)].
Induction of various cellular responses mediated by such TNF family cytokines is believed to be initiated by their binding to specific cell receptors. Two distinct TNF receptors of approximately 55-kDa (TNFR1) and 75-kDa (TNFR2) have been identified [Hohman et al., J. Biol. Chem., 264:14927–14934 (1989); Brockhaus et al., Proc. Natl. Acad. Sci., 87:3127–3131 (1990); EP 417,563, published Mar. 20, 1991] and human and mouse cDNAs corresponding to both receptor types have been isolated and characterized [Loetscher et al., Cell, 61:351 (1990); Schall et al., Cell, 61:361 (1990); Smith et al., Science, 248:1019–1023 (1990); Lewis et al., Proc. Natl. Acad. Sci., 88:2830–2834 (1991); Goodwin et al., Mol. Cell. Biol., 11:3020–3026 (1991)]. Extensive polymorphisms have been associated with both TNF receptor genes [see, e.g., Takao et al., Immunogenetics, 37:199–203 (1993)]. Both TNFRs share the typical structure of cell surface receptors including extracellular, transmembrane and intracellular regions. The extracellular portions of both receptors are found naturally also as soluble TNF-binding proteins [Nophar, Y. et al., EMBO J., 9:3269 (1990); and Kohno, T. et al., Proc. Natl. Acad. Sci. U.S.A., 87:8331 (1990)]. More recently, the cloning of recombinant soluble TNF receptors was reported by Hale et al. [J. Cell. Biochem. Supplement 15F, 1991, p. 113 (P424)].
The extracellular portion of type 1 and type 2 TNFRs (TNFR1 and TNFR2) contains a repetitive amino acid sequence pattern of four cysteine-rich domains (CRDs) designated 1 through 4, starting from the NH2-terminus. Each CRD is about 40 amino acids long and contains 4 to 6 cysteine residues at positions which are well conserved [Schall et al., supra; Loetscher et al., supra; Smith et al., supra; Nophar et al., supra; Kohno et al., supra]. In TNFR1, the approximate boundaries of the four CRDs are as follows: CRD1-amino acids 14 to about 53; CRD2-amino acids from about 54 to about 97; CRD3-amino acids from about 98 to about 138; CRD4-amino acids from about 139 to about 167. In TNFR2, CRD1 includes amino acids 17 to about 54; CRD2-amino acids from about 55 to about 97; CRD3-amino acids from about 98 to about 140; and CRD4-amino acids from about 141 to about 179 [Banner et al., Cell 73:431–435 (1993)]. The potential role of the CRDs in ligand binding is also described by Banner et al., supra.
A similar repetitive pattern of CRDs exists in several other cell-surface proteins, including the p75 nerve growth factor receptor (NGFR) [Johnson et al., Cell, 47:545 (1986); Radeke et al., Nature, 325:593 (1987)], the B cell antigen CD40 [Stamenkovic et al., EMBO J., 8:1403 (1989)], the T cell antigen OX40 [Mallet et al., EMBO J., 9:1063 (1990)] and the Fas antigen [Yonehara et al., supra and Itoh et al., Cell 66:233–243 (1991)]. CRDs are also found in the soluble TNFR (sTNFR)-like T2 proteins of the Shope and myxoma poxviruses [Upton et al., Virology, 160:20–29 (1987); Smith et al., Biochem. Biophys. Res. Commun., 176:335 (1991); Upton et al., Virology, 184:370 (1991)]. Optimal alignment of these sequences indicates that the positions of the cysteine residues are well conserved. These receptors are sometimes collectively referred to as members of the TNF/NGF receptor superfamily. Recent studies on p75NGFR showed that the deletion of CRD1 [Welcher, A. A. et al., Proc. Natl. Acad. Sci. USA, 88:159–163 (1991)] or a 5-amino acid insertion in this domain [Yan, H. and Chao, M. V., J. Biol. Chem., 266:12099–12104 (1991)] had little or no effect on NGF binding [Yan, H. and Chao, M. V., supra]. p75 NGFR contains a proline-rich stretch of about 60 amino acids, between its CRD4 and transmembrane region, which is not involved in NGF binding [Peetre, C. et al., Eur. J. Hematol., 41:414–419 (1988); Seckinger, P. et al., J. Biol. Chem., 264:11966–11973 (1989); Yan, H. and Chao, M. V., supra]. A similar proline-rich region is found in TNFR2 but not in TNFR1.
The TNF family ligands identified to date, with the exception of lymphotoxin-α, are type II transmembrane proteins, whose C-terminus is extracellular. In contrast, most receptors in the TNF receptor (TNFR) family identified to date are type I transmembrane proteins. In both the TNF ligand and receptor families, however, homology identified between family members has been found mainly in the extracellular domain (“ECD”). Several of the TNF family cytokines, including TNF-α, Apo-1 ligand and CD40 ligand, are cleaved proteolytically at the cell surface; the resulting protein in each case typically forms a homotrimeric molecule that functions as a soluble cytokine. TNF receptor family proteins are also usually cleaved proteolytically to release soluble receptor ECDs that can function as inhibitors of the cognate cytokines.
Recently, other members of the TNFR family have been identified. Such newly identified members of the TNFR family include CAR1, HVEM and osteoprotegerin (OPG) [Brojatsch et al., Cell, 87:845–855 (1996); Montgomery et al., Cell, 87:427–436 (1996); Marsters et at., J. Biol. Chem., 272:14029–14032 (1997); Simonet et al., Cell, 89:309–319 (1997)]. Unlike other known TNFR-like molecules, Simonet et al., supra, report that OPG contains no hydrophobic transmembrane-spanning sequence.
Moreover, a new member of the TNF/NGF receptor family has been identified in mouse, a receptor referred to as “GITR” for “glucocorticoicd-induced tumor necrosis factor receptor family-related gene” [Nocentini et al., Proc. Natl. Acad. Sci. USA 94:6216–6221 (1997)]. The mouse GITR receptor is a 228 amino acid type I transmembrane protein that is expressed in normal mouse T lymphocytes from thymus, spleen and lymph nodes. Expression of the mouse GITR receptor was induced in T lymphocytes upon activation with anti-CD3 antibodies, Con A or phorbol 12-myristate 13-acetate. It was speculated by the authors that the mouse GITR receptor was involved in the regulation of T cell receptor-mediated cell death.
In Marsters et al., Curr. Biol., 6:750 (1996), investigators describe a full length native sequence human polypeptide, called Apo-3, which exhibits similarity to the TNFR family in its extracellular cysteine-rich repeats and resembles TNFR1 and CD95 in that it contains a cytoplasmic death domain sequence [see also Marsters et al., Curr. Biol., 6:1669 (1996)]. Apo-3 has also been referred to by other investigators as DR3, wsl-1 and TRAMP [Chinnaiyan et al., Science, 274:990 (1996); Kitson et al., Nature, 384:372 (1996); Bodmer et al., Immunity, 6:79 (1997)].
Pan et al. have disclosed another TNF receptor family member referred to as “DR4” [Pan et al., Science, 276:111–113 (1997)]. The DR4 was reported to contain a cytoplasmic death domain capable of engaging the cell suicide apparatus. Pan et al. disclose that DR4 is believed to be a receptor for the ligand known as Apo-2 ligand or TRAIL.
In Sheridan et al., Science, 277:818–821 (1997) and Pan et al., Science, 277:815–818 (1997), another molecule believed to be a receptor for the Apo-2 ligand (TRAIL) is described. That molecule is referred to as DR5 (it has also been alternatively referred to as Apo-2). Like DR4, DR5 is reported to contain a cytoplasmic death domain and be capable of signaling apoptosis.
In Sheridan et al., supra, a receptor called DcR1 (or alternatively, Apo-2DcR) is disclosed as being a potential decoy receptor for Apo-2 ligand (TRAIL). Sheridan et al. report that DcR1 can inhibit Apo-2 ligand function in vitro. See also, Pan et al., supra, for disclosure on the decoy receptor referred to as TRID.
For a review of the TNF family of cytokines and their receptors, see Gruss and Dower, supra.
As presently understood, the cell death program contains at least three important elements—activators, inhibitors, and effectors; in C. elegans, these elements are encoded respectively by three genes, Ced-4, Ced-9 and Ced-3 [Steller, Science, 267:1445 (1995); Chinnaiyan et al., Science 275:1122–1126 (1997); Wang et al., Cell, 90:1–20 (1997)]. Two of the TNFR family members, TNFR1 and Fas/Apo1 (CD95), can activate apoptotic cell death [Chinnaiyan and Dixit, Current Biology, 6:555–562 (1996); Fraser and Evan, Cell; 85:781–784 (1996)]. TNFR1 is also known to mediate activation of the transcription factor, NF-κB [Tartaglia et al., Cell, 74:845–853 (1993); Hsu et al., Cell, 84:299–308 (1996)]. In addition to some ECD homology, these two receptors share homology in their intracellular domain (ICD) in an oligomerization interface known as the death domain [Tartaglia et al., supra; Nagata, Cell, 88:355 (1997)]. Death domains are also found in several metazoan proteins that regulate apoptosis, namely, the Drosophila protein, Reaper, and the mammalian proteins referred to as FADD/MORT1, TRADD, and RIP [Cleaveland and Ihle, Cell, 81:479–482 (1995)].
Upon ligand binding and receptor clustering, TNFR1 and CD95 are believed to recruit FADD into a death-inducing signalling complex. CD95 purportedly binds FADD directly, while TNFR1 binds FADD indirectly via TRADD [Chinnaiyan et al., Cell, 81:505–512 (1995); Boldin et al., J. Biol. Chem., 270:387–391 (1995); Hsu et al., supra; Chinnaiyan et al., J. Biol. Chem., 271:4961–4965 (1996)]. It has been reported that FADD serves as an adaptor protein which recruits the Ced-3-related protease, MACHα/FLICE (caspase 8), into the death signalling complex [Boldin et al., Cell, 85:803–815 (1996); Muzio et al., Cell, 85:817–827 (1996)]. MACHα/FLICE appears to be the trigger that sets off a cascade of apoptotic proteases, including the interleukin-1β converting enzyme (ICE) and CPP32/Yama, which may execute some critical aspects of the cell death programme [Fraser and Evan, supra].
It was recently disclosed that programmed cell death involves the activity of members of a family of cysteine proteases related to the C. elegans cell death gene, ced-3, and to the mammalian IL-1-converting enzyme, ICE. The activity of the ICE and CPP32/Yama proteases can be inhibited by the product of the cowpox virus gene, crmA [Ray et al., Cell, 69:597–604 (1992); Tewari et al., Cell, 81:801–809 (1995)]. Recent studies show that CrmA can inhibit TNFR1- and CD95-induced cell death [Enari et al., Nature, 375:78–81 (1995); Tewari et al., J. Biol. Chem., 270:3255–3260 (1995)].
As reviewed recently by Tewari et al., TNFR1, TNFR2 and CD40 modulate the expression of proinflammatory and costimulatory cytokines, cytoline receptors, and cell adhesion molecules through activation of the transcription factor, NF-κB [Tewari et al., Curr. Op. Genet. Develop., 6:39–44 (1996)]. NF-κB is the prototype of a family of dimeric transcription factors whose subunits contain conserved Rel regions [Verma et al., Genes Develop., 2:2723–2735 (1996); Baldwin, Ann. Rev. Immunol., 14:649–681 (1996)]. In its latent form, NF-κB is complexed with members of the IκB inhibitor family; upon inactivation of the IκB in response to certain stimuli, released NF-κB translocates to the nucleus where it binds to specific DNA sequences and activates gene transcription.
10. PRO382
Proteases are enzymatic proteins which are involved in a large number of very important biological processes in mammalian and non-mammalian organisms. Numerous different protease enzymes from a variety of different mammalian and non-mammalian organisms have been both identified and characterized, including the serine proteases which exhibit specific activity toward various serine-containing proteins. The mammalian protease enzymes play important roles in biological processes such as, for example, protein digestion, activation, inactivation, or modulation of peptide hormone activity, and alteration of the physical properties of proteins and enzymes.
In light of the important physiological roles played by protease enzymes, efforts are currently being undertaken by both industry and academia to identify new, native protease homologs. Many of these efforts are focused on the screening of mammalian recombinant DNA libraries to identify the coding sequences for novel membrane-bound receptor proteins. Examples of screening methods and techniques are described in the literature [see, for example, Klein et al., Proc. Natl. Acad. Sci., 93:7108–7113 (1996); U.S. Pat. No. 5,536,637)]. We herein describe the identification of novel polypeptides having homology to serine protease enzymes, designated herein as PRO382 polypeptides.
11. PRO545
The ADAM (A Disintegrin And Metalloprotease) family of proteins of which meltrin is a member may have an important role in cell interactions and in modulating cellular responses. [see, for example, Gilpin et al., J. Biol. Chem., 273(1):157–166(1998)]. The ADAM proteins have been implicated in carcinogenesis. Meltrin-α (ADAM12) is a myoblast gene product reported to be required for cell fusion. [Harris et al., J. Cell. Biochem., 67(1):136–142 (1997), Yagami-Hiromasa et al., Nature, 377:652–656 (1995)]. The meltrins contain disintegrin and metalloprotease domains and are implicated in cell adhesive events involved in development, through the integrin-binding disintegrin domain, but also have an anti-adhesive function through a zinc-dependent metalloprotease domain. [Alfandari et al., Devel. Biol., 182(2):314–330 (1997)]. Given the medical importance of cell fusion and modulation of cellular responses in carcinogenesis and other disease mechanisms, efforts are currently being under taken to identify new, native proteins which are involved in cell fusion and modulation of cellular responses. We describe herein the identification of a novel polypeptide which has homology to meltrin, designated herein as PRO545.
12. PRO617
CD24 is a protein that is associated with the cell surface of a variety of different cells of the mammalian immune system, including for example, neutrophils, monocytes and some lymphocytes, for example, B lymphocytes. CD24 has been shown to be a ligand for the platelet-associated surface glycoprotein P-selectin (also known as granule membrane protein-140 or GMP-140), a glycoprotein that is constitutively synthesized in both platelets and endothelial cells and becomes exposed on the surface of platelets when those cells become activated. In this way, P-selectin mediates the calcium-dependent adhesion of activated platelets and endothelial cells to the various cells of the immune system that express one or more ligands for the P-selectin molecule, particularly CD24. This mechanism allows for recruitment of immune system cells to locations where they are most needed, for example, sites of injury. Thus, there is substantial interest in identifying novel polypeptides that exhibit homology to the cell surface antigens of the immune system cells. We herein describe the identification and characterization of a novel polypeptide having homology to the CD24 protein, wherein that novel polypeptide is herein designated PRO617.
13. PRO700
Protein-disulfide isomerase (PDI) is a catalyst of disulfide formation and isomerization during protein folding. It has two catalytic sites housed in two domains homologous to thioredoxin, one near the N terminus and the other near the C terminus. [See for example, Gilbert H F, J. Biol. Chem., 47:29399–29402 (1997), Mayfield K J, Science, 278:1954–1957 (1997) and Puig et al., J. Biol. Chem., 52:32988–32994 (1997)]. PDI is useful for formation of natural type disulfide bonds in a protein which is produced in aprokaryotic cell. (See also, U.S. Pat. Nos. 5,700,659 and 5,700,678).
Thus, PDI and molecules related thereto are of interest, particularly for ability to catalyze the formation of disulfide bonds. Moreover, these molecules are generally of interest in the study of redox reactions and related processes. PDI and related molecules are further described in Darby, et al., Biochemistry 34, 11725–11735 (1995). We herein describe the identification and characterization of novel polypeptides having homology to protein disulfide isomerase, designated herein as PRO700 polypeptides.
14. PRO702
Conglutinin is a bovine serum protein that was originally described as a vertebrate lectin protein and which belongs to the family of C-type lectins that have four characteristic domains, (1) an N-terminal cysteine-rich domain, (2) a collagen-like domain, (3) a neck domain and (4) a carbohydrate recognition domain (CRD). Recent reports have demonstrated that bovine conglutinin can inhibit hemagglutination by influenza A viruses as a result of their lectin properties (Eda et al., Biochem. J. 316:43–48 (1996)). It has also been suggested that lectins such as conglutinin can function as immunoglobulin-independent defense molecules due to complement-mediated mechanisms. Thus, conglutinin has been shown to be useful for purifying immune complexes in vitro and for removing circulating immune complexes from patients plasma in vivo (Lim et al., Biochem. Biophys. Res. Commun. 218:260–266 (1996)). We herein describe the identification and characterization of a novel polypeptide having homology to the conglutinin protein, designated herein as PRO702.
15. PRO703
Very-long-chain acyl-CoA synthetase (“VLCAS”) is a long-chain fatty acid transport protein which is active in the cellular transport of long and very long chain fatty acids. [see for example, Uchida et al., J Biochem (Tokyo) 119(3):565–571 (1996) and Uchiyama et al., J Biol Chem 271(48):30360–30365 (1996). Given the biological importance of fatty acid transport mechanisms, efforts are currently being under taken to identify new, native proteins which are involved in fatty acid transport. We describe herein the identification of a novel polypeptide which has homology to VLCAS, designated herein as PRO703.
16. PRO705
The glypicans are a family of glycosylphosphatidylinositol (GPI)-anchored proteoglycans that, by virtue of their cell surface localization and possession of heparin sulfate chains, may regulate the responses of cells to numerous heparin-binding growth factors, cell adhesion molecules and extracellular matrix components. Mutations in one glypican protein cause of syndrome of human birth defects, suggesting that the glypicans may play an important role in development (Litwack et al., Dev. Dyn. 211:72–87 (1998)). Also, since the glypicans may interact with the various extracellular matrices, they may also play important roles in wound healing (McGrath et al., Pathol. 183:251–252 (1997)). Furthermore, since glypicans are expressed in neurons and glioma cells, they may also play an important role in the regulation of cell division and survival of cells of the nervous system (Liang et al., J. Cell. Biol. 139:851–864 (1997)). It is evident, therefore, that the glypicans are an extremely important family of proteoglycans. There is, therefore, substantial interest in identifying novel polypeptides having homology to members of the glypican family. We herein describe the identification and characterization of a novel polypeptide having homology to K-glypican, designated herein as PRO705.
17. PRO708
Aryl sulfatases are enzymes that exist in a number of different isoforms, including aryl sulfatase A (ASA), aryl sulfatase B (ASB) and aryl sulfatase C (ASC), and that function to hydrolyze a variety of different aromatic sulfates. Aryl sulfatases have been isolated from a variety of different animal tissues and microbial sources and their structures and functions have been extensively studied (see, e.g., Nichol and Roy, J. Biochem. 55:643–651 (1964)). ASA deficiency has been reported to be associated with metachromatic leukodystrophy (MLD) (Giles et al., Prenat. Diagn. 7(4):245–252 (1987) and Herska et al., Am. J. Med. Genet. 26(3):629–635 (1987)). Additionally, other groups have reported that aryl sulfatases have been found in high levels in natural killer cells of the immune system and have hypothesized a possible role for these enzymes in NK cell-mediated cellular lysis (see, e.g., Zucker-Franklin et al., Proc. Natl. Acad. Sci. USA 80(22):6977–6981 (1983)). Given the obvious physiological importance of the aryl sulfatase enzymes, there is a substantial interest in identifying novel aryl sulfatase homolog polypeptides. We herein describe the identification and characterization of novel polypeptides having homology to the aryl sulfatases, wherein these novel polypeptides are herein designated PRO708 polypeptides.
18. PRO320
Fibulin-1 is a cysteine-rich, calcium-binding extracellular matrix (ECM) component of basement membranes and connective tissue elastic fibers and plasma protein, which has four isoforms, A–D, derived from alternative splicing. Fibulin-1 is a modular glycoprotein with amino-terminal anaphlatoxin-like modules followed by nine epidermal growth factor (EGF)-like modules and, depending on alternative splicing, four possible carboxyl termini. Fibulin-2 is a novel extracellular matrix protein frequently found in close association with microfibrils containing either fibronectin or fibrillin. There are multiple forms of fibulin-1 that differ in their C-terminal regions that are produced through the process of alternative splicing of their precursor RNA. [see for example Tran et al., Matrix Biol 15(7):479–493 (1997).]
Northern and Western blotting analysis of 16 cell lines established from tumors formed in athymic mice and malignant cell lines derived from patients indicate that low expression of fibulin-1D plays a role in tumor formation and invasion. [Qing et al., Oncogene, 18:2159–2168 (1997)]. Ovarian-cancer cells are characterized by their ability to invade freely the peritoneal cavity. It has been demonstrated that estradiol stimulates the proliferation of estrogen-receptor (ER)-positive ovarian-cancer cells, as well as expression of fibulin-1. Studies on the effect of fibulin-1 on motility of the MDA-MB231 breast-cancer cell line, indicated inhibition of haptotactic migration of MDA-MB231 cells, and the authors concluded that fibulin-1 can inhibit cancer cell motility in vitro and therefore has the potential to inhibit tumor invasion. [Hayashido et al., Int J Cancer, 75(4):654–658 (1998)].
Thus, fibulin, and molecules related thereto are of interest, particularly for the use of preventing cancer. Moreover, these molecules are generally of interest in the study of connective tissue and attachment molecules and related mechanisms. Fibulin and related molecules are further described in Adams, et al., J. Mol. Biol., 272(2):226–36 (1997); Kielty and Shuttleworth, Microsc. Res. Tech., 38(4):413–27 (1997); and Child. J. Card. Surg. 12(2Supp.):131–5 (1997).
We herein describe the identification and characterization of novel polypeptides having homology to fibulin, designated herein as PRO320 polypeptides.
19. PRO324
Oxidoreductases are enzymes that catalyze a reaction in which two molecules of a compound interact so that one molecule is oxidized and the other is reduced, with a molecule of water entering the reaction. There are many different types of oxidoreductase enzymes that play very important physiological roles in the mammalian organism. Some of the most important oxidoreductases include, for example, lyases, lactases, cholesterol oxidases, and the like. These enzymes play roles in such essential processes as digestion, signal transduction, maintenance of ionic homeostasis, and the like. As such, given that oxidoreductase enzymes find various essential uses in the mammalian organism, there is a substantial interest in identifying novel oxidoreductase enzyme homologs. We herein describe the identification and characterization of a novel polypeptide having homology to oxidoreductases, designated herein as PRO324.
20. PRO351
Prostasin is a novel human serine proteinase purified from human seminal fluid. Immunohistochemical localization reveals that prostasin is present in epithelial cells and ducts of the prostate gland. The cDNA for prostasin has been cloned and characterized. Southern blot analysis, following a reverse transcription polymerase chain reaction, indicates that prostasin mRNA is expressed in prostate, liver, salivary gland, kidney, lung, pancreas, colon, bronchus, renal proximal tubular cells, and prostate carcinoma LNCaP cells. Cellular localization of prostasin mRNA was identified within epithelial cells of the human prostate gland by in situ hybridization histochemistry. [See for example, Yu et al., J Biol Chem. (1994) 269(29): 18843–18848, and Yu et al., J Biol Chem. (1994) 270(22):13483–13489].
Thus, prostasin, and molecules related thereto are of interest, particularly for the study, diagnosis and treatment of medical conditions involving the prostate. Prostasin and related molecules are further described in Yu et al., Genomics (1996) 32(3):334–340. We herein describe the identification and characterization of novel polypeptides having homology to prostasin, designated herein as PRO351 polypeptides.
21. PRO352
Butyrophilin is a milk glycoprotein that constitutes more than 40% of the total protein associated with the fat globule membrane in mammalian milk. Expression of butyrophilin mRNA has been shown to correlate with the onset of milk fat production toward the end pregnancy and is maintained throughout lactation. Butyrophilin has been identified in bovine, murine and human (see Taylor et al., Biochim. Biophys. Acta 1306:1–4 (1996), Ishii et al., Biochim. Biophys. Acta 1245:285–292 (1995), Mather et al., J. Dairy Sci. 76:3832–3850 (1993) and Banghart et al., J. Biol. Chem. 273:4171–4179 (1998)) and is a type I transmembrane protein that is incorporated into the fat globulin membrane. It has been suggested that butyrophilin may play a role as the principle scaffold for the assembly of a complex with xanthine dehydrogenase/oxidase and other proteins that function in the budding and release of milk-fat globules from the apical surface during lactation (Banghart et al., supra).
Given that butyrophilin plays an obviously important role in mammalian milk production, there is substantial interest in identifying novel butyrophilin homologs. We herein describe the identification and characterization of a novel polypeptide having homology to butyrophilin, designated herein as PRO352.
22. PRO381
The immunophilins are a family of proteins that function as receptors for immunosuppressant drugs, such as cyclosporin A, FK506, and rapamycin. The immunophilins occur in two separate classes, (1) the FK506-binding proteins (FKBPs), which bind to FK506 and rapamycin, and (2) the cyclophilins, which bind to cyclosporin A. With regard to the FK506-binding proteins, it has been reported that the FK506/FKBP complex functions to inhibit the activity of the serine/threonine protein phosphatase 2B (calcineurin), thereby providing immunosuppressant activity (Gold, Mol. Neurobiol. 15:285–306 (1997)). It has also been reported that the FKBP immunophilins are found in the mammalian nervous system and may be involved in axonal regeneration in the central nervous system through a mechanism that is independent of the process by which immunosuppression is achieved (Gold, supra). Thus, there is substantial interest in identifying novel polypeptides having homology to the FKBP immunophilins. We herein describe the identification and characterization of a novel polypeptide having homology to an FKBP immunophilins protein, designated herein as PRO381.
23. PRO386
Mammalian cell membranes perform very important functions relating to the structural integrity and activity of various cells and tissues. Of particular interest in membrane physiology is the study of transmembrane ion channels which act to directly control a variety of physiological, pharmacological and cellular processes. Numerous ion channels have been identified including calcium (Ca), sodium (Na) and potassium (K) channels, each of which have been analyzed in detail to determine their roles in physiological processes in vertebrate and insect cells.
One type of cell membrane-associated ion channel, the sodium channel, plays an extremely important role in a cell's ability to maintain ionic homeostasis as well as transmit intracellular and extracellular signals. Voltage-gated sodium channels in brain neurons have been shown to be complexes of a pore-forming alpha unit with smaller beta-1 and beta-2 subunits (Isom et al., Cell 83:433–442 (1995)). Given the obvious importance of sodium channels in cellular homeostasis arid other important physiological functions, there is a significant interest in identifying novel polypeptides having homology to sodium channel subunits. We herein describe the identification and characterization of a novel polypeptide having homology to the beta-2 subunit of the rat sodium channel, designated herein as PRO386.
24. PRO540
Lecithin-cholesterol acyltransferase (“LCAT”), also known as phosphatidylcholine-sterol acyltransferase is a key enzyme in the intravascular metabolism of high density lipoproteins, specifically in the process of cholesterol metabolism. [see, for example, Brousseau et al., J. Lipid Res., 38(12):2537–2547 (1997), Hill et al., Biochem. J., 294:879–884 (1993), and Drayna et al., Nature 327 (6123):632–634 (1987)]. Given the medical importance of lipid metabolism, efforts are currently being under taken to identify new, native proteins which are involved in lipid transport. We describe herein the identification of a novel polypeptide which has homology to LCAT, designated herein as PRO540.
25. PRO615
Synaptogyrin is a synaptic vesicle protein that is uniformly distributed in the nervous system. The cDNA encoding synaptogyrin has been cloned and sequenced and the sequence predicts a protein with a molecular mass of 25,900 D with four membrane-spanning domains. Synaptogyrin has been implicated in membrane traffic to and from the plasma membrane. Stenius et al., J. Cell. Biol. 131(6–2):1801–1809 (1995). In addition, a novel isoform of synaptogyrin called cellugyrin exhibits sequence identity with synaptogyrin. In rat tissues, cellugyrin and synaptogyrins are expressed in mirror image patterns. Cellugyrin is ubiquitously present in all tissues tested with the lowest levels in brain tissue, whereas synaptogyrin protein is only detectable in brain. In rat tissues, cellugyrin and synaptogyrins are expressed in mirror image patterns. The synaptic vesicle protein synaptogyrin may be a specialized version of a ubiquitous protein, cellugyrin, with the two proteins sharing structural similarity but differing in localization. This finding supports the emerging concept of synaptic vesicles as the simplified and specialized form of a generic trafficking organelle. [Janz et al., J. Biol. Chem. 273(5):2851–2857 (1998)]. The sequence for cellugyrin derived from the Norway rat, Rattus norvegicus has been deposited in the Genbank database on 23, Dec. 1997, designated accession number AF039085. See also, Janz et al., J. Biol. Chem. 273 (1998), in press.
Given the medical importance of synaptic transmission, efforts are currently being under taken to identify new, native proteins that may be part of a simplified and specialized generic trafficking organelle in the form of synaptic vesicles. We describe herein the identification of a novel polypeptide which has homology to synaptogyrin, designated herein as PRO615.
26. PRO618
Enteropeptidase is a key enzyme in the intestinal digestion cascade specifically cleaves the acidic propeptide from trypsinogen to yield active trypsin. This cleavage initiates a cascade of proteolytic reactions leading to the activation of many pancreatic zymogens. See, for example, Matsushima et al., J. Biol. Chem. 269(31):19976–19982 (1994), Kitamoto et al., Proc. Nat. Acad. Sci., 91(16):7588–7592 (1994). Enterokinase (enteropeptidase) is a related to mammalian serine proteases involved indigestion, coagulation, and fibrinolysis. LaVallie et al., J Biol Chem., 268(31):23311–23317 (1993).
Given the medical importance of digestive processes, efforts are currently being under taken to identify new, native proteins that may be involved in digestion, coagulation, and fibrinolysis. We describe herein the identification of a novel polypeptide which has homology to enteropeptidase, designated herein as PRO618.
27. PRO719
Lipoprotein lipase is a key enzyme that mediates the hydrolysis of triglycerides and phospholipids present in circulating plasma lipoproteins (Dugi et al., J. Biol. Chem. 270:25396–25401 (1995)). Moreover, lipoprotein lipase has been shown to mediate the uptake of lipoproteins into cells, wherein cellular uptake of lipoproteins is initiated by binding of lipoprotein lipase to cell surface proteoglycans and to the low density lipoprotein (LDL) receptor-related protein (Krapp et al., J. Lipid Res. 36:2362–2373 (1995)). Thus, it is clear that lipoprotein lipase plays an extremely important role in lipoprotein and cholesterol metabolism. There is, therefore, substantial interest in identifying novel polypeptides that share sequence homology and/or biological activity with lipoprotein lipase. We herein describe the identification and characterization of a novel polypeptide having sequence homology to lipoprotein lipase H, designated herein as PRO719.
28. PRO724
The low density lipoprotein (LDL), receptor is a membrane-bound protein that plays a key role in cholesterol homeostasis, mediating cellular uptake of lipoprotein particles by high affinity binding to its ligands,  apolipoprotein (apo) B-100 and apoE. The ligand-binding domain of the LDL receptor contains 7 cysteine-rich repeats of approximately 40 amino acids, wherein each repeat contains 6 cysteines, which form 3 intra-repeat disulfide bonds. These unique structural features provide the LDL receptor with its ability to specifically interact with apo B-100 and apoE, thereby allowing for transport of these lipoprotein particles across cellular membranes and metabolism of their components. Soluble fragments containing the extracellular domain of the LDL receptor have been shown to retain the ability to interact with its specific lipoprotein ligands (Simmons et al., J. Biol. Chem. 272:25531–25536 (1997)). Thus, it is clear that the LDL receptor is intimately involved in important physiological activities related to cholesterol metabolism. As such, there is substantial interest in identifying novel LDL receptor homolog proteins. We herein describe the identification and characterization of a novel polypeptide having homology to the human LDL receptor protein, designated herein as PRO724.
29. PRO772
Expression of the human gene A4 is enriched in the colonic epithelium and is transcriptionally activated on differentiation of colonic epithelial cells in vitro (Oliva et al., Arch. Biochem. Biophys. 302:183–192 (1993) and Oliva et al., Am. J. Physiol. 272:C957–C965 (1997)). A4 cDNA contains an open reading frame that predicts a polypeptide of approximately 17 kilodaltons in size. Hydropathy analysis of the A4 protein revealed four putative membrane-spanning alpha-helices. Immunocytochemical studies of cells expressing A4 protein indicated that expression is localized to the endoplasmic reticulum. The four membrane-spanning domains and the biophysical characteristics of the A4 protein suggest that it belongs to a family of integral membrane proteins called proteolipids, some of which multimerize to form ion channels. In fact, preliminary evidence has suggested that A4 may itself multimerize and take on the properties of an ion channel (Oliva et al., Am. J. Physiol. 272:C957–C965 (1997)). Given the importance of ion channels in maintaining cellular homeostasis, there is a significant interest in identifying novel polypeptides having homology to known and putative ion channels. We herein describe the identification and characterization of a novel polypeptide having homology to the putative ion channel protein, A4, designated herein as PRO772.
30. PRO852
Proteases are enzymatic proteins which are involved in a large number of very important biological processes in mammalian and non-mammalian organisms. Numerous different protease enzymes from a variety of different mammalian and non-mammalian organisms have been both identified and characterized. The mammalian protease enzymes play important roles in many different biological processes including, for example, protein digestion, activation, inactivation, or modulation of peptide hormone activity, and alteration of the physical properties of proteins and enzymes.
In light of the important physiological roles played by protease enzymes, efforts are currently being undertaken by both industry and academia to identify new, native protease homologs. Many of these efforts are focused on the screening of mammalian recombinant DNA libraries to identify the coding sequences for novel secreted and membrane-bound receptor proteins. Examples of screening methods and techniques are described in the literature [see, for example, Klein et al., Proc. Natl. Acad. Sci., 93:7108–7113 (1996); U.S. Pat. No. 5,536,637)]. We herein describe the identification of novel polypeptides having homology to various protease enzymes, designated herein as PRO852 polypeptides.
31. PRO853
Studies have reported that the redox state of the cell is an important determinant of the fate of the cell. Furthermore, reactive oxygen species have been reported to be cytotoxic, causing inflammatory disease, including tissue necrosis, organ failure, atherosclerosis, infertility, birth defects, premature aging, mutations and malignancy. Thus, the control of oxidation and reduction is important for a number of reasons, including the control and prevention of strokes, heart attacks, oxidative stress, hypertension and may be associated with the development of malignancies. The levels of antioxidant enzymes, such as reductases, which catalyze the conversion of reactive oxygen species to water have been shown to be low in cancer cells. In particular, malignant prostate epithelium may have lowered expression of such antioxidant enzymes [Baker et ., Prostate 32(4):229–233 (1997)]. In this regard, reductases, are of interest. In addition, the transcription factors, NF-kappa B and AP-1, are known to be regulated by redox state and to affect the expression of a large variety of genes thought to be involved in the pathogenesis of AIDS, cancer, atherosclerosis and diabetic complications. Publications further describing this subject matter include Engman et al., Anticancer Res. (Greece), 17:4599–4605 (1997), Kelsey, et al., Br. J. Cancer, 76(7):8524 (1997); Friedrich and Weiss, J. Theor. Biol., 187(4):529–40 (1997) and Pieulle, et al., J. Bacteriol., 179(18):5684–92 (1997). Given the physiological importance of redox reactions in vivo, efforts are currently being under taken to identify new, native proteins which are involved in redox reactions. We describe herein the identification of a novel prostate specific polypeptide which has sequence similarity to reductase, designated herein as PRO853.
32. PRO860
Neurofascin is a member of the L1 subgroup of the cellular adhesion molecule (“CAM”) family of nervous system adhesion molecules and is involved in cellular aggregation. Cell-cell recognition and patterning of cell contacts have a critical role in mediating reversible assembly of a wide variety or transcellular complexes in the nervous system. Cell interactions may be regulated through modulation of ankyrin binding to neurofascin. See, for example, Tuvia et al., Proc. Nat Acad. Sci., 94(24) 12957–12962 (1997). Neurofascin has been described as a member of the L1 subgroup of the immunoglobulin superfamily implicated in neurite extension during embryonic development for which numerous isoforms have been detected at various stages of development. See also Hassel et al., J. Biol. Chem., 272(45) 28742–28749 (1997), Grumet., Cell. Tissue Res. 290(2) 423–428 (1997), Garver et al., J. Cell. Biol., 137:703–714 (1997), and Lambert et al., J. Neurosci., 17:7025-7-36 (1997).
Given the physiological importance of cellular adhesion molecules and development of the nervous system in vivo, efforts are currently being under taken to identify new, native proteins which are involved in regulation of cellular interactions in the nervous system. We describe herein the identification and characterization of a novel polypeptide which has sequence similarity to neurofascin, designated herein as PRO860.
33. PRO846
The CMRF35 monoclonal antibody was used to identify a cell membrane antigen, designated CMRF35, which is present on the surface of monocytes, neutrophils, a proportion of peripheral blood T and B lymphocytes and lymphocytic cell lines. The CMRF35 cDNA encodes a novel integral membrane glycoprotein member of the immunoglobulin (Ig) gene superfamily. The molecule comprises (a) a single extracellular Ig variable domain remarkably similar to the Fc receptor for polymeric IgA and IgM, (b) a membrane-proximal domain containing a high proportion of proline, serine and threonine residues that was predicted to be heavily O-glycosylated, (c) an unusual transmembrane anchor that contained a glutamic acid and a proline residue and (d) a short cytoplasmic tail. Transcripts encoding the CMRF35 protein have been detected in early monocytic cell lines, in peripheral blood T cells and in some B lymphoblastoid cell lines, confirming the results of immunocytological staining. Jackson et al., Eur. J. Immunol. 2.2(5):1157–1163 (1992). CMRF-35 molecules are differentially expressed in hematopoietic cells, and the expression of the antigen was shown to be markedly influenced by stimulation with mitogens and cytokines. See, for example, Clark et al., Exp. Hematol. 25(8):759 (1997), Daish et al., Immunol. 79(1):55–63 (1993), and Clark et al., Tissue Antigens 48:461 (1996).
Given the physiological importance of the immune system and antigens associated with various immune system cells, efforts are currently being under taken to identify new, native proteins which are expressed on various cells of the immune system. We describe herein the identification of a novel polypeptide which has sequence similarity to CMRF35, designated herein as PRO846.
34. PRO862
Lysozyme is a protein which is widely distributed in several human tissues and secretions including milk, tears and saliva. It has been demonstrated to hydrolyze linkages between N-acetylglucosamines. It has been demonstrated to be an inhibitor of chemotaxis and of the production of toxic oxygen free radicals and may also have some role in the calcification process. As such, there is substantial interest in identifying novel polypeptides having homology to lysozyme. We describe herein the identification of a novel polypeptide which has sequence similarity to lysozyme.
35. PRO864
Wnt-4 is a secreted glycoprotein which correlates with, and is required for, kidney tubulogenesis. Mice lacking Wnt-4 activity fail to form pretubular cell aggregates; however, other aspects of mesenchymal and ureteric development are unaffected. Thus, Wnt-4 appears to act as an autoinducer of the mesenchyme to epithelial transition that underlies nephron development. Stark et al., Nature ;372(6507):679–683 (1994). In addition, members of the Wnt gene family code for cysteine-rich, secreted proteins, which are differentially expressed in the developing brain and possibly act as intercellular signaling molecules. A Wnt gene, e.g., Wnt-1 is known to be essential for specification of the midbrain cell fate. Yoshioka et al., Biochem. Biophys. Res. Commun. 203(3):1581–1588 (1994). Several member of the Wnt family of secreted factors are strongly implicated as regulators of mammary cellular growth and differentiation. Shimizu et al., Cell Growth Differ. 8(12) 1349–1358. Wnt-4 is normally expressed in early pregnancy. Wnt-4 may therefore be a local signal driving epithelial branching in pregnancy. Edwards P A, Biochem Soc Symp.63:21–34 (1998). See also, Lipschutz J H, Am. J. Kidney Dis. 31(3):383–397, (1998). We describe herein the identification and characterizaton of a novel polypeptide which has sequence similarity to Wnt4, designated herein as PRO864.
36. PRO792
At least two cell-derived signals have been shown to be necessary for the induction of immunoglobulin isotype switching in B-cells. The first signal is given by either of the soluble lymphokines, interleukin (IL)-4 or IL-13, which induce germline epsilon transcript expression, but this alone is insufficient to trigger secretion of immunoglobulin E (IgE). The second signal is provided by a physical interaction between B-cells and activated T-cells, basophils and mast cells, and it has been shown that the CD40/CD40 ligand pairing is crucial for mediating IgE synthesis. Additionally, amongst the numerous pairs of surface adhesion molecules that are involved in IgE synthesis, the CD23/CD21 pair appears to play a key role in the generation of IgE. CD23 is a protein that is positively and negatively regulated by factors which increase or decrease IgE production, respectively. Antibodies to CD23 have been shown to inhibit IL-4 induced human IgE production in vitro and to inhibit antigen-specific IgE responses in a rat model, in an isotype selective manner (Bonnefoy et al., Eur. Respir. J. Suppl. 22:63S–66S (1996)). CD23 interacts with CD21 on B-cells, preferentially driving IgE production. Given that the CD23 protein plays an extremely important role in the induction of a mammalian IgE response, there is significant interest in identifying novel polypeptides having homology to CD23. We herein describe the identification and characterization of a novel polypeptide having homology to CD23, designated herein as PRO792.
37. PRO866
Mindin and spondin proteins are secreted proteins that are structurally related to one another and which have been identified in a variety of organisims. For example, Higashijima et al., Dev Biol. 192:211–227 (1997) have reported the identification of spondin and mindin expression in floor plate cells in the zebrafish embryonic axis, thereby suggesting that mindin and spondin proteins play important roles in embryonic development. This same group has reported that mindin and spondin proteins function as extracellular matrix proteins that have a high affinity for the basal lamina. (Id.). It has been reported that F-spondin is a secreted protein that promotes neural adhesion and neurite extension (Klar et al., Cell 69:95–110 (1992) and that M-spondin is an extracellular matrix protein that localizes to muscle attachment sites in Drosophila (Umemiya et al., Dev. Biol. 186:165–176 (1997)). Thus, there is significant interest in identifying novel polypeptides having homology to the mindin and spondin proteins. We herein describe the identification and characterization of a novel polypeptide having homology to mindin2 and mindin1, designated herein as PRO866.
38. PRO871
Cyclophilins are a family of proteins that bind to cyclosporin A and possess peptidyl-prolyl cis-trans isomerase activity (Sherry et al., Proc. Natl. Acad. Sci. USA 95:1758–1763 (1998)). In addition, cyclophilins are secreted by activated cells and act in a cytokine-like manner, presumably via signaling through a cell surface cyclophilin receptor. Host cell-derived cyclophilin A has been shown to be incorporated into HIV-1 virions and its incorporation has been shown to be essential for viral infectivity. Thus, one or more the cyclophilins may be directly associated with HIV-1 infectivity. Given the obvious importance of the cyclophilin proteins, there is substantial interest in identifying novel polypeptides which have sequence homology to one or more of the cyclophilin proteins. We herein describe the identification and characterization of a novel polypeptide having homology to cyclophilin-like protein CyP-60, designated herein as PRO871.
39. PRO873
Enzymatic proteins play important roles in the chemical reactions involved in the digestion of foods, the biosynthesis of macromolecules, the controlled release and utilization of chemical energy, and other processes necessary to sustain life. Enzymes have also been shown to play important roles in combating various diseases and disorders. For example, liver carboxylesterases have been reported to assist in sensitizing human tumor cells to the cancer prodrugs. Danks et al., report that stable expression of the cDNA encoding a carboxylesterase in Rh30 human rhabdomyosarcoma cells increased the sensitivity of the cells to the CPT-11 cancer prodrug 8.1-fold. Cancer Res. (1998) 58(1):20–22. The authors propose that this prodrug/enzyme combination could be exploited therapeutically in a manner analogous to approaches currently under investigation with the combinations of ganciclovir/herpes simplex virus thymidine kinase and 5-fluorocytosine/cytosine deaminase. van Pelt et al. demonstrated that a 55 kD human liver carboxylesterase inhibits the invasion of Plasmodium falciparum malaria sporozoites into primary human hepatocytes in culture. J Hepatol (1997) 27(4):688–698.
Carboxylesterases have also been found to be of importance in the detoxification of drugs, pesticides and other xenobiotics. Purified human liver carboxylesterases have been shown to be involved in the metabolism of various drugs including cocaine and heroin. Prindel et al. describe the purification and cloning of a broad substrate specificity human liver carboxylesterase which catalyzes the hydrolysis of cocaine and heroin and which may play an important role in the degradation of these drugs in human tissues. J. Biol. Chem. (1997) 6:272(23):14769–14775. Brzenzinski et al. describe a spectrophotometric competitive inhibition assay used to identify drug or environmental esters that are metabolized by carboxylesterases. Drug Metab Dispos (1997) 25(9):1089–1096.
In light of the important physiological roles played by carboxylesterases, efforts are being undertaken by both industry and academia to identify new, native carboxylesterase homologs. We herein describe the identification and characterization of a novel polypeptide having homology to carboxylesterase, designated herein as PRO873.
40. PRO940
CD33 is a cell-surface protein that is a member of the sialoadhesin family of proteins that are capable of mediating sialic-acid dependent binding with distinct specificities for both the type of sialic acid and its linkage to subterminal sugars. CD33 is specifically expressed in early myeloid and some monocyte cell lineages and has been shown to be strongly associated with various myeloid tumors including, for example, acute non-lymphocytic leukemia (ANLL). As such, CD33 has been suggested as a potential target for the treatment of cancers associated with high level expression of the protein. There is, therefore, significant interest in the identification of novel polypeptides having homology to CD33. In fact, one CD33 homolog (designated CD33L) has already been identified and described (see Takei et al., Cytogenet. Cell Genet. 78:295–300 (1997)). We herein describe the identification of another novel polypeptide having homology to CD33, designated herein as PRO940. The novel polypeptide described herein also exhibits significant homology to the human OB binding proteins designated HSU71382—1 and HSU71383—1 in the Dayhoff database (version 35.45 SwissProt 35).
41. PRO941
Cadherins are a large family of transmembrane proteins. Cadherins comprise a family of calcium-dependent glycoproteins that function in mediating cell-cell adhesion in virtually all solid tissues of multicellular organisms. At least cadherins 1–13 as well as types B, E, EP, M, N, P and R have been identified and characterized. Among the functions cadherins are known for, with some exceptions, are that cadherins participate in cell aggregation and are associated with cell-cell adhesion sites. Recently, it has been reported that while all cadherins share multiple repeats of a cadherin specific motif believed to correspond to folding of extracellular domains, members of the cadherin superfamily have divergent structures and, possibly, functions. In particular it has been reported that members of the cadherin superfamily are involved in signal transduction. See, Suzuki, J. Cell Biochem., 61(4):531–542 (1996). Cadherins are further described in Tanihara et al., J. Cell Sci., 107(6):1697–1704 (1994), Aberle et al., J. Cell Biochem., 61(4):514–523 (1996) and Tanihara et al., Cell Adhes. Commun., 2(1):15–26 (1994). We herein describe the identification and characterization of a novel polypeptide having homology to a cadherin protein, designated herein as PRO941.
42. PRO944
Clostridium perfringens enterotoxin (CPE) is considered to be the virulence factor responsible for causing the symptoms of C. perfringens type A food poisoning and may also be involved in other human and veterinary illnesses (McClane, Toxicon. 34:1335–1343 (1996)). CPE carries out its adverse cellular functions by binding to an approximately 50 kD cell surface receptor protein designated the Clostridium perfringens enterotoxin receptor (CPE-R) to form an approximately 90,000 kD complex on the surface of the cell. cDNAs encoding the CPE-R protein have been identified characterized in both human and mouse (Katra et al., J. Cell Biol. 136:1239–1247 (1997) and Katahira et al., J. Biol. Chem. 272:26652–26658 (1997)). Since the CPE toxin has been reported to cause a variety of illnesses in mammalian hosts and those illnesses are initiated by binding of the CPE toxin to the CPE-R, there is significant interest in identifying novel CPE-R homologs. We herein describe the identification and characterization of a novel polypeptide having homology to the CPE-R, designated herein as PRO944.
43. PRO983
Membrane-bound proteins include not only cell-surface membrane-bound proteins, but also proteins that are found on the surface of intracellular vesicles. These vesicles are involved in exocytosis, which is the fusion of secretory vesicles with the cellular plasma membrane, and have two main functions. One is the discharge of the vesicle contents into the extracellular space, and the second is the incorporation of new proteins and lipids into the plasma membrane itself. Exocytosis can be either constitutive or regulated. All eukaryotic cells exhibit constitutive exocytosis, which is marked by the immediate fusion of the secretory vesicle after formation. In contrast, regulated exocytosis results in the accumulation of the secretory vesicles that fuse with the plasma membrane upon receipt of an appropriate signal by vesicle-associated membrane proteins. Usually, this signal is an increase in the cytosolic free Ca2+ concentration. However, regulated exocytosis that is independent of Ca2+ has been reported (see, e.g. Fujita-Yoshigaki et al. J. Biol. Chem. (1996) 31:271(22):13130–13134). Regulated exocytosis is crucial to many specialized cells, including neurons (neurotransmitter release from synaptic vesicles), adrenal chromaffin cells (adrenaline secretion), pancreatic acinar cells (digestive enzyme secretion), pancreatic β-cells (insulin secretion), mast cells (histamine secretion), mammary cells (milk protein secretion), sperm (enzyme secretion), egg cells (creation of fertilization envelope) and adipocytes (insertion of glucose transporters into the plasma membrane).
Disorders involving exocytosis are known. For example, inflammatory mediator release from mast cells leads to a variety of disorders, including asthma. Similarly, Chediak-Higashi Syndrome (CHS) is a rare autosomal recessive disease in which neutrophils, monocytes and lymphocytes contain giant cytoplasmic granules. Accordingly, the proteins involved in exocytosis are of paramount interest and efforts are being undertaken by both industry and academia to identify new, vesicle-associated proteins. For example, Skehel et al. identified a 33-kilodalton membrane protein in Aplysia, termed VAP-33, which is required for the exocytosis of neurotransmitter. Science (1995) 15:269(5230):1580–1583, and Neuropharmacology (1995) 34(11):1379–1385.
Many efforts are focused on the screening of mammalian recombinant DNA libraries to identify the coding sequences for novel vesicle-associated membrane proteins. It is an object of the invention to provide proteins having homology to the vesicle associated protein, VAP-33, designated herein as PRO983.
44. PRO1057
Proteases are enzymatic proteins which are involved in a large number of very important biological processes in mammalian and non-mammalian organisms. Numerous different protease enzymes from a variety of different mammalian and non-mammalian organisms have been both identified and characterized. The mammalian protease enzymes play important roles in many different biological processes including, for example, protein digestion, activation, inactivation, or modulation of peptide hormone activity, and alteration of the physical properties of proteins and enzymes.
In light of the important physiological roles played by protease enzymes, efforts are currently being undertaken by both industry and academia to identify new, native protease homologs. Many of these efforts are focused on the screening of mammalian recombinant DNA libraries to identify the coding sequences for novel secreted proteins. Examples of screening methods and techniques are described in the literature [see, for example, Klein et al., Proc. Natl. Acad. Sci., 93:7108–7113 (1996); U.S. Pat. No. 5,536,637)]. We herein describe the identification of novel polypeptides having homology to various protease enzymes, designated herein as PRO1057 polypeptides.
45. PRO1071
Thrombospondin-1 is a trimeric high molecular weight glycoprotein that is released from platelet alpha-granules in response to thrombin stimulation and that is also a transient component of the extracellular matrix in developing and repairing tissues (Adams, Int. J. Biochem. Cell Biol. 29:861–865 (1997) and Qian et al., Proc. Soc. Exp. Biol. Med. 212:199–207 (1996)). A variety of factors regulate thrombospondin expression and the protein is degraded by both extracellular and intracellular routes. Thrombospondin-1 functions as a cell adhesion molecule and also modulates cell movement, cell proliferation, neurite outgrowth and angiogenesis. As such, there is substantial interest in identifying novel polypeptides having homology to thrombospondin. We herein describe the identification and characterization of a novel polypeptide having homology to thrombospondin, designated herein as PRO 1071.
46. PRO1072
Studies have reported that the redox state of the cell is an important determinant of the fate of the cell. Furthermore, reactive oxygen species have been reported to be cytotoxic, causing inflammatory disease, including tissue necrosis, organ failure, atherosclerosis, infertility, birth defects, premature aging, mutations and malignancy. Thus, the control of oxidation and reduction is important for a number of reasons, including the control and prevention of strokes, heart attacks, oxidative stress, hypertension and may be associated with the development of malignancies. The levels of antioxidant enzymes, such as reductases, which catalyze the conversion of reactive oxygen species to water have been shown to be low in cancer cells. In particular, malignant prostate epithelium may have lowered expression of such antioxidant enzymes [Baker et al., Prostate 32(4):229–233 (1997)]. In this regard, reductases, are of interest. In addition, the transcription factors, NF-kappa B and AP-1, are known to be regulated by redox state and to affect the expression of a large variety of genes thought to be involved in the pathogenesis of AIDS, cancer, atherosclerosis and diabetic complications. Publications further describing this subject matter include Engman et al., Anticancer Res. (Greece), 17:4599–4605 (1997), Kelsey, et al., Br. J. Cancer, 76(7):852–854 (1997); Friedrich and Weiss, J. Theor. Biol., 187(4):529–40 (1997) and Pieulle, et al., J. Bacteriol., 179(18):5684–92 (1997). Given the physiological importance of redox reactions in vivo, efforts are currently being under taken to identify new, native proteins which are involved in redox reactions. We describe herein the identification of a novel polypeptide which has sequence similarity to reductase enzymes, designated herein as PRO1072.
47. PRO1075
Protein disulfide isomerase is an enzymatic protein which is involved in the promotion of correct refolding of proteins through the establishment of correct disulfide bond formation. Protein disulfide isomerase was initially identified based upon its ability to catalyze the renaturation of reduced denatured RNAse (Goldberger et al., J. Biol. Chem. 239:1406–1410 (1964) and Epstein et al., Cold Spring Harbor Symp. Quant. Biol. 28:439–449 (1963)). Protein disulfide isomerase has been shown to be a resident enzyme of the endoplasmic reticulum which is retained in the endoplasmic reticulum via a -KDEL or -HDEL amino acid sequence at its C-terminus.
Given the importance of disulfide bond-forming enzymes and their potential uses in a number of different applications, for example in increasing the yield of correct refolding of recombinantly produced proteins, efforts are currently being undertaken by both industry and academia to identify new, native proteins having homology to protein disulfide isomerase. Many of these efforts are focused on the screening of mammalian recombinant DNA libraries to identify the coding sequences for novel protein disulfide isomerase homologs. Examples of screening methods and techniques are described in the literature [see, for example, Klein et al., Proc. Natl. Acad. Sci. 93:7108–7113 (1996); U.S. Pat. No. 5,536,637)]. We herein describe a novel polypeptide having homology to protein disulfide isomerase, designated herein as PRO1075.
48. PRO181
In Drosophila, the dorsal-ventral polarity of the egg chamber depends on the localization of the oocyte nucleus and the gurken RNA to the dorsal-anterior corner of the oocyte. Gurken protein presumably acts as a ligand for the drosophila EGF receptor (torpedo/DER) expressed in the somatic follicle cells surrounding the oocyte. Cornichon is a gene required in the germline for dorsal-ventral signaling (Roth et al., Cell 81:967–978 (1995)). Cornichon, gurken and torpedo also function in an earlier signaling event that establishes posterior follicle cell fates and specifies the anterior-posterior polarity of the egg chamber. Mutations in any or all of these genes prevent the formation of a correctly polarized microtubule cytoskeleton required for proper localization of the anterior and posterior determinants bicoid and oskar and for the asymmetric positioning of the oocyte nucleus. Thus, it is clear that the cornichon gene product plays an important role in early development. We herein describe the identification and characterization of a novel polypeptide having homology to the cornichon protein, designated herein as PRO181.
49. PRO195
Efforts are currently being undertaken to identify and characterize novel transmembrane proteins. We herein describe the identification and characterization of a novel transmembrane polypeptide, designated herein as PRO195.
50. PRO865
Efforts are currently being undertaken to identify and characterize novel secreted proteins. We herein describe the identification and characterization of a novel secreted polypeptide, designated herein as PRO865.
51. PRO827
VLA-2 is an cell-surface integrin protein that has been identified and characterized in a number of mammalian organisms, including both mouse and human. VLA-2 has been shown to be a receptor on the surface of cells for echovirus-1 (EV-1) which mediates infection of VLA-2-expressing cells by EV-1 (Zhang et al., Virology 235(2):293–301 (1997) and Bergelson et al., Science 255:1718–1720 (1992)). VLA-2 has also been shown to mediate the interaction of collagen with endothelium during in vitro vascular tube formation (Jackson et al., Cell Biol. Int. 18(9):859–867 (1994)). Various other integrin proteins that share various degrees of amino acid sequence homology with VLA-2 have been identified and characterized in a variety of mammalian organism. These integrins have been reported to play important roles in a variety of different physiological functions. Therefore, there is significant interest in identifying novel polypeptides having homology to one or more of the integrin proteins. We herein describe the identification and characterization of a novel polypeptide having homology to VLA-2 integrin protein, designated herein as PRO827.
52. PRO1114
Many important cytokine proteins have been identified and characterized and shown to signal through specific cell surface receptor complexes. For example, the class II cytokine receptor family (CRF2) includes the interferon receptors, the interleukin-10 receptor and the tissue factor CRFB4 (Spencer et al., J. Exp. Med. 187:571–578 (1998) and Kotenko et al., EMBO J. 16:5894–5903 (1997)). Thus, the multitude of biological activities exhibited by the various cytokine proteins is absolutely dependent upon the presence of cytokine receptor proteins on the surface of target cells. There is, therefore, a significant interest in identifying and characterizing novel polypeptides having homology to one or more of the cytokine receptor family. We herein describe the identification and characterization of a novel polypeptide having homology to cytokine receptor family-4 proteins, designated herein as PRO1117.
Interferons (IFNs) encompass a large family of secreted proteins occurring in vertebrates. Although they were originally named for their antiviral activity, growing evidence supports a critical role for IFNs in cell growth and differentiation (Jaramillo et al., Cancer Investigation 13(3):327–338 (1995)). IFNs belong to a class of negative growth factors having the ability to inhibit the growth of a wide variety of cells with both normal and transformed phenotypes. IFN therapy has been shown to be beneficial in the treatment of human malignancies such as Karposi's sarcoma, chronic myelogenous leukemia, non-Hodgkin's lymphoma, and hairy cell leukemia as well as in the treatment of infectious diseases such as hepatitis B (Gamliel et al., Scanning Microscopy 2(1):485–492 (1988), Einhorn et al., Med. Oncol. & Tumor Pharmacother. 10:25–29 (1993), Ringenberg et al., Missouri Medicine 85(1):21–26 (1988), Saracco et al., Journal of Gastroenterology and Hepatology 10:668–673 (1995), Gonzalez-Mateos et al., Hepato-Gastroenterology 42:893–899 (1995) and Malaguarnera et al., Pharmacotherapy 17(5):998–1005 (1997)).
Interferons can be classified into two major groups based upon their primary sequence. Type I interferons, IFN-α and IFN-β, are encoded by a superfamily of intronless genes consisting of the IFN-α gene family and a single IFN-β gene that are thought to have arisen from a common ancestral gene. Type I interferons may be produced by most cell types. Type II IFN, or IFN-γ, is restricted to lymphocytes (T cells and natural killer cells) and is stimulated by nonspecific T cell activators or specific antigens in vivo.
Although both type I and type II IFNs produce similar antiviral and antiproliferative effects, they act on distinct cell surface receptors, wherein the binding is generally species specific (Langer et al., Immunol. Today 9:393–400 (1988)). Both IFN-α and IFN-β bind competitively to the same high affinity type I receptor, whereas IFN-γ binds to a distinct type II receptor. The presence and number of IFN receptors on the surface of a cell does not generally reflect the sensitivity of the cell to IFN, although it is clear that the effects of the IFN protein is mediated through binding to a cell surface interferon receptor. As such, the identification and characterization of novel interferon receptor proteins is of extreme interest.
We herein describe the identification and characterization of novel interferon receptor polypeptides, designated herein as “PRO1114 interferon receptor” polypeptides. Thus, the PRO1114 polypeptides of the present invention represents a novel cell surface interferon receptor.
53. PRO237
Carbonic anhydrase is an enzymatic protein that which aids carbon dioxide transport and release in the mammalian blood system by catalyzing the synthesis (and the dehydration) of carbonic acid from (and to) carbon dioxide and water. Thus, the actions of carbonic anhydrase are essential for a variety of important physiological reactions in the mammal. As such, there is significant interest in the identification and characterization of novel polypeptides having homology to carbonic anhydrase. We herein describe the identification and characterization of a novel polypeptide having homology to carbonic anhydrase, designated herein as PRO237.
54. PRO541
Numerous trypsin inhibitory proteins have been identified and characterized (see, e.g., Yamakawa et al., Biochim. Biophys. Acta 1395:202–208 (1998) and Mizuki et al., Mammalian Genome 3:274–280 (1992)). Trypsin inhibitor proteins play important roles in a variety of different physiological and biological pathways and are specifically involved in such processes as the regulation of protein degradation, digestion, and the like. Given the important roles played by such enzymatic proteins, there is significant interest in identifying and characterizing novel polypeptides having homology to known trypsin inhibitor proteins. We herein describe the identification and characterization of a novel polypeptide having homology to a trypsin inhibitor protein, designated herein as PRO541.
55. PRO273
Leukocytes include monocytes, macrophages, basophils, and eosinophils and play an important role in the immune response. These cells are important in the mechanisms initiated by T and/or B lymphocytes and secrete a range of cytokines which recruit and activate other inflammatory cells and contribute to tissue destruction.
Thus, investigation of the regulatory processes by which leukocytes move to their appropriate destination and interact with other cells is critical. Currently, leukocytes are thought to move from the blood to injured or inflamed tissues by rolling along the endothelial cells of the blood vessel wall. This movement is mediated by transient interactions between selectins and their ligands. Next, the leukocyte must move through the vessel wall and into the tissues. This diapedesis and extravasation step involves cell activation which promotes a more stable leukocyte-endothelial cell interaction, again mediated by integrins and their ligands.
Chemokines are a large family of structurally related polypeptide cytokines. These molecules stimulate leukocyte movement and may explain leukocyte trafficking in different inflammatory situations. Chemokines mediate the expression of particular adhesion molecules on endothelial cells, and they produce chemoattractants which activate specific cell types. In addition, the chemokines stimulate proliferation and regulate activation of specific cell types. In both of these activities, chemokines demonstrate a high degree of target cell specificity.
The chemokine family is divided into two subfamilies based on whether two amino terminal cysteine residues are immediately adjacent (C-C) or separated by one amino acid (C-X-C). Chemokines of the C-X-C family generally activate neutrophils and fibroblasts while the C-C chemokines act on a more diverse group of target cells including monocytes/macrophages, basophils, eosinophils and T lymphocytes. The known chemokines of both subfamilies are synthesized by many diverse cell types as reviewed in Thomson A. (1994) The Cytokine Handbook, 2 d Ed. Academic Press, N.Y. Chemokines are also reviewed in Schall T J (1994) Chemotactic Cytokines: Targets for Therapeutic Development. International Business Communications, Southborough Mass. pp 180–270; and in Paul W E (1993) Fundamental Immunology, 3rd Ed. Raven Press, N.Y. pp 822–826.
Known chemokines of the C-X-C subfamily include macrophage inflammatory proteins alpha and beta (MIP-1 and MIP-2 ), interleukin-8 (IL-8), and growth regulated protein (GRO-alpha and beta).
MIP-2 was first identified as a 6 kDa heparin binding protein secreted by the mouse macrophage cell line RAW 264.7 upon stimulation with lipopolysaccharide (LPS). MIP-2 is a member of the C-X-C (or CXC) subfamily of chemokines. Mouse MIP-2 is chemotactic for human neutrophils and induces local neutrophil infiltration when injected into the foot pads of mice. Rat MIP-2 shows 86% amino acid homology to the mouse MIP-2 and is chemotactic for rat neutrophils but does not stimulate migration of rat alveolar macrophages or human peripheral blood eosinophils or lymphocytes. In addition, the rat MIP-2 has been shown to stimulate proliferation of rat alveolar epithelial cells but not fibroblasts.
Current techniques for diagnosis of abnormalities in inflamed or diseased issues mainly rely on observation of clinical symptoms or serological analyses of body tissues or fluids for hormones, polypeptides or various metabolites. Problems exist with these diagnostic techniques. First, patients may not manifest clinical symptoms at early stages of disease. Second, serological tests do not always differentiate between invasive diseases and genetic syndromes. Thus, the identification of expressed chemokines is important to the development of new diagnostic techniques, effective therapies, and to aid in the understanding of molecular pathogenesis.
To date, chemokines have been implicated in at least the following conditions: psoriasis, inflammatory bowel disease, renal disease, arthritis, immune-mediated alopecia, stroke, encephalitis, MS, hepatitis, and others. In addition, non-ELR-containing chemokines have been implicated in the inhibition of angiogenesis, thus indicating that these chemokines have a rule in tumor vascularization and tumorigenesis.
Therefore it is the object of this invention to identify polypeptides and nucleic acids encoding the same which have sequence identity and similarity with cytokine-induced neutrophil chemoattractants, MIP-1, MIP-2, and other related proteins. The efforts of this object are provided herein.
56. PRO701
Beta neurexins and neuroligins are plasma membrane proteins that are displayed on the neuronal cell surface. Neuroligin 1 is enriched in synaptic plasma membranes and acts as a splice site-specific ligand for beta neurexins as described in Ichtchenko, et al., Cell, 81(3):435–443 (1995). The extracellular sequence of neuroligin 1 is composed of a catalytically inactive esterase domain homologous to acetylcholinesterase. Neuroligin 2 and 3 are similar in structure and sequence to neuroligin 1. All neuroligins contain an N-terminal hydrophobic sequence with the characteristics of a cleaved signal peptide followed by a large esterase homology domain, a highly conserved single transmembrane region, and a short cytoplasmic domain. The three neuroligins are alternatively spliced at the same position and are expressed at high levels only in the brain. Tight binding of the three neuroligins to beta neurexins is observed only for beta neurexins lacking an insert in splice site 4. Thus, neuroligins constitute a multigene family of brain-specific proteins with distinct isoforms that may have overlapping functions in mediating recognition processes between neurons, see Ichtchenko, et al., J. Biol. Chem., 271(5):2676–2682 (1996). Moreover, neurexins and neuroligins have been reported as functioning as adhesion molecules in a Ca2+ dependent reaction that is regulated by alternative splicing of beta neurexins, i.e., see Nguyen and Sudhof, J. Biol. Chem., 272(41):26032–26039 (1997). Given the foregoing, membrane bound proteins are of interest. More generally, membrane-bound proteins and receptors can play an important role in the formation, differentiation and maintenance of multicellular organisms. The fate of many individual cells, e.g., proliferation, migration, differentiation, or interaction with other cells, is typically governed by information received from other cells and/or the immediate environment. This information is often transmitted by secreted polypeptides (for instance, mitogenic factors, survival factors, cytotoxic factors, differentiation factors, neuropeptides, and hormones) which are, in turn, received and interpreted by diverse cell receptors or membrane-bound proteins. Such membrane-bound proteins and cell receptors include, but are not limited to, cytokine receptors, receptor kinases, receptor phosphatases, receptors involved in cell-cell interactions, and cellular adhesin molecules like selectins and integrins. For instance, transduction of signals that regulate cell growth and differentiation is regulated in part by phosphorylation of various cellular proteins. Protein tyrosine kinases, enzymes that catalyze that process, can also act as growth factor receptors. Examples include fibroblast growth factor receptor and nerve growth factor receptor.
Membrane-bound proteins and receptor molecules have various industrial applications, including as pharmaceutical and diagnostic agents. Receptor immunoadhesins, for instance, can be employed as therapeutic agents to block receptor-ligand interaction. The membrane-bound proteins can also be employed for screening of potential peptide or small molecule inhibitors of the relevant receptor/ligand interaction.
Efforts are being undertaken by both industry and academia to identify new, native membrane-bound receptor proteins, particularly those having sequence identity and/or similarity with neuroligins 1, 2 and 3. Many efforts are focused on the screening of mammalian recombinant DNA libraries to identify the coding sequences for novel secreted and membrane-bound receptor proteins. Examples of screening methods and techniques are described in the literature [see, for example, Klein et al., Proc. Natl. Acad. Sci., 93:7108–7113 (1996); U.S. Pat. No. 5,536,637)]. The results of such efforts are provided herein.
57. PRO704
VIP36 is localized to the Golgi apparatus and the cell surface, and belongs to a family of legume lectin homologues in the animal secretory pathway that might be involved in the trafficking of glycoproteins, glycolipids, or both. It is further believed that VIP36 binds to sugar residues of glycosphingolipids and/or gycosylphosphatidyl-inositol anchors and might provide a link between the extracellular/luminal face of glycolipid rafts and the cytoplasmic protein segregation machinery. Further regarding VIP36, it is believed that there is a signal at its C-terminus that matches an internalization consensus sequence which confers its ability to cycle between the plasma membrane and Golgi. See, Fiedler, et al, EMBO J., 13(7):1729–1740 (1994); Fiedler and Simons, J. Cell Sci., 109(1):271–276 (1996); Itin, et al., MBO J., 14(10):2250–2256 (1995). It is believed that VIP36 is either the same as or very closely related to the human GP36b protein. VIP36 and/or GP36b are of interest.
More generally, vesicular, cytoplasmic, extracellular and membrane-bound proteins play important roles in the formation, differentiation and maintenance of multicellular organisms. The fate of many individual cells, e.g., proliferation, migration, differentiation, or interaction with other cells, is typically governed by information received from other cells and/or the immediate environment. This information is often transmitted by secreted polypeptides (for instance, mitogenic factors, survival factors, cytotoxic factors, differentiation factors, neuropeptides, and hormones) which are, in turn, received and interpreted by diverse cell receptors or membrane-bound proteins. These secreted polypeptides or signaling molecules normally pass through the cellular secretory pathway to reach their site of action in the extracellular environment, usually at a membrane-bound receptor protein.
Secreted proteins have various industrial applications, including use as pharmaceuticals, diagnostics, biosensors and bioreactors. In fact, most protein drugs available at present, such as thrombolytic agents, interferons, interleukins, erythropoietins, colony stimulating factors, and various other cytokines, are secretory proteins. Their receptors, which are membrane-bound proteins, also have potential as therapeutic or diagnostic agents. Receptor immunoadhesins, for instance, can be employed as therapeutic agents to block receptor-ligand interaction. Membrane-bound proteins can also be employed for screening of potential peptide or small molecule inhibitors of the relevant receptor/ligand interaction. Such membrane-bound proteins and cell receptors include, but are not limited to, cytokine receptors, receptor kinases, receptor phosphatases, receptors involved in cell-cell interactions, and cellular adhesin molecules like selectins and integrins. Transduction of signals that regulate cell growth and differentiation is regulated in part by phosphorylation of various cellular proteins. Protein tyrosine kinases, enzymes that catalyze that process, can also act as growth factor receptors. Examples include fibroblast growth factor receptor and nerve growth factor receptor.
Efforts are being undertaken by both industry and academia to identify new, native vesicular, cytoplasmic, secreted and membrane-bound receptor proteins, particularly those having sequence identity and/or similarity with VIP36. Many efforts are focused on the screening of mammalian recombinant DNA libraries to identify the coding sequences for novel secreted and membrane-bound receptor proteins. Examples of screening methods and techniques are described in the literature [see, for example, Klein et al., Proc. Natl. Acad. Sci., 93:7108–7113 (1996); U.S. Pat. No. 5,536,637)].
58. PRO706
Acid phophatase proteins are secreted proteins which dephophorylate terminal phosphate groups under acidic pH conditions. Acid phophatases contain a RHGXRXP amino acid sequence, which is predicted to be mechanistically significant. Acid phosphatases may have important functions in the diagnosis and treatment of human diseases. For example, prostatic acid phosphatase is a secreted protein uniquely expressed in prostatic tissue and prostate cancer. The level of prostatic acid phosphatase is a potential prognostic factor for local and biochemical control in prostate cancer patients treated with radiotherapy, as described in Lankford et al., Int. J. Radiat. Oncol. Biol. Phys. 38(2): 327–333 (1997). Research suggests that a cellular immune response to prostatic acid phosphatase may mediate destructive autoimmune prostatitis, and that xenogeneic forms of prostatic acid phosphatase may prove useful for immunotherapy of prostate cancer. See Fong et al., J. Immunol. 169(7): 3113–3117 (1997). Seminal prostatic acid phosphatase levels correlate significantly with very low sperm levels (oligospermia) in individuals over 35, see Singh et al., Singapore Med. J. 37(6): 598–599 (1996). Thus, prostatic acid phosphatase has been implicated in a variety of human diseases, and may have an important function in diagnosis and therapy of these diseases. A series of aminobenzylphosphatic acid compounds are highly potent inhibitors of prostatic acid phosphatase, as described in Beers et al., Bioorg. Med. Chem. 4(10):1693–1701 (1996).
More generally, extracellular proteins play an important role in the formation, differentiation and maintenance of multicellular organisms. The fate of many individual cells, e.g., proliferation, migration, differentiation, or interaction with other cells, is typically governed by information received from other cells and/or the immediate environment. This information is often transmitted by secreted polypeptides (for instance, mitogenic factors, survival factors, cytotoxic factors, differentiation factors, neuropeptides, and hormones) which are, in turn, received and interpreted by diverse cell receptors or membrane-bound proteins. These secreted polypeptides or signaling molecules normally pass through the cellular secretory pathway to reach their site of action in the extracellular environment.
Secreted proteins have various industrial applications, including pharmaceuticals, diagnostics, biosensors and bioreactors. Most protein drugs available at present, such as thrombolytic agents, interferons, interleukins, erythropoietins, colony stimulating factors, and various other cytokines, are secretory proteins. Their receptors, which are membrane proteins, also have potential as therapeutic or diagnostic agents. Efforts are being undertaken by both industry and academia to identify new, native secreted proteins, particularly those having sequence identity with prostate acid phosphatase precursor and lysosomal acid phosphatase precursor and in some cases, those having identity with DNA found in fetal heart. Many efforts are focused on the screening of mammalian recombinant DNA libraries to identify the coding sequences for novel secreted proteins. Examples of screening methods and techniques are described in the literature [see, for example, Klein et al., Proc. Natl. Acad. Sci., 93:7108–7113 (1996); U.S. Pat. No. 5,536,637)].
59. PRO707
Cadherins are a large family of transmembrane proteins. At least cadherins 1–13 as well as types B, E, EP, M, N, P and R have been characterized. Among the functions cadherins are known for, with some exceptions, cadherins participate in cell aggregation and are associated with cell-cell adhesion sites. Cadherins are further described in Tanihara, et al., J. Cell Sci., 107(6): 1697–1704 (1994) and Tanihara, et al., Cell Adhes. Commun., 2(1):15–26 (1994). Moreover, it has been reported that some members of the cadherin superfamily are involved in general cell-cell interaction processes including transduction. See, Suzuki, J. Cell Biochem., 61(4):531–542 (1996). Therefore, novel members of the cadherin superfamily are of interest.
More generally, all novel proteins are of interest, including membrane-bound proteins. Membrane-bound proteins and receptors can play an important role in the formation, differentiation and maintenance of multicellular organisms. The fate of many individual cells, e.g., proliferation, migration, differentiation, or interaction with other cells, is typically governed by information received from other cells and/or the immediate environment. This information is often transmitted by secreted polypeptides (for instance, mitogenic factors, survival factors, cytotoxic factors, differentiation factors, neuropeptides, and hormones) which are, in turn, received and interpreted by diverse cell receptors or membrane-bound proteins. Such membrane-bound proteins and cell receptors include, but are not limited to, cytokine receptors, receptor kinases, receptor phosphatases, receptors involved in cell-cell interactions, and cellular adhesin molecules like selectins and integrins. For instance, transduction of signals that regulate cell growth and differentiation is regulated in part by phosphorylation of various cellular proteins. Protein tyrosine kinases, enzymes that catalyze that process, can also act as growth factor receptors. Examples include fibroblast growth factor receptor and nerve growth factor receptor.
Membrane-bound proteins and receptor molecules have various industrial applications, including as pharmaceutical and diagnostic agents. Receptor immunoadhesins, for instance, can be employed as therapeutic agents to block receptor-ligand interaction. The membrane-bound proteins can also be employed for screening of potential peptide or small molecule inhibitors of the relevant receptor/ligand interaction.
Efforts are being undertaken by both industry and academia to identify new, native secreted and membrane-bound receptor proteins, particularly membrane bound proteins having identity with cadherins. The results of such efforts are provided herein.
60. PRO322
Proteases are enzymatic proteins which are involved in a large number of very important biological processes in mammalian and non-mammalian organisms. Numerous different protease enzymes from a variety of different mammalian and non-mammalian organisms have been both identified and characterized, including the serine proteases which exhibit specific activity toward various serine-containing proteins. The mammalian protease enzymes play important roles in biological processes such as, for example, protein digestion, activation, inactivation, or modulation of peptide hormone activity, and alteration of the physical properties of proteins and enzymes.
Neuropsin is a novel serine protease whose mRNA is expressed in the central nervous system. Mouse neuropsin has been cloned, and studies have shown that it is involved in the hippocampal plasticity. Neuropsin has also been indicated as associated with extracellular matrix modifications and cell migrations. See, generally, Chen, et al., Neurosci., 7(2):5088–5097 (1995) and Chen, et al., J. Histochem. Cytochem., 46:313–320 (1998).
Efforts are being undertaken by both industry and academia to identify new, native membrane-bound or secreted proteins, particularly those having homology to neuropsin, serine protease, neurosin and trypsinogen. Many efforts are focused on the screening of mammalian recombinant DNA libraries to identify the coding sequences for novel secreted and membrane-bound receptor proteins. Examples of screening methods and techniques are described in the literature [see, for example, Klein et al., Proc. Natl. Acad. Sci., 93:7108–7113 (1996); U.S. Pat. No. 5,536,637)].
61. PRO526
Protein-protein interactions include those involved with receptor and antigen complexes and signaling mechanisms. As more is known about the structural and functional mechanisms underlying protein-protein interactions, protein-protein interactions can be more easily manipulated to regulate the particular result of the protein-protein interaction. Thus, the underlying mechanisms of protein-protein interactions are of interest to the scientific and medical community.
All proteins containing leucine-rich repeats are thought to be involved in protein-protein interactions. Leucine-rich repeats are short sequence motifs present in a number of proteins with diverse functions and cellular locations. The crystal structure of ribonuclease inhibitor protein has revealed that leucine-rich repeats correspond to beta-alpha structural units. These units are arranged so that they form a parallel beta-sheet with one surface exposed to solvent, so that the protein acquires an unusual, nonglobular shape. These two features have been indicated as responsible for the protein-binding functions of proteins containing leucine-rich repeats. See, Kobe and Deisenhofer, Trends Biochem. Sci., 19(10):415–421 (October 1994).
A study has been reported on leucine-rich proteoglycans which serve as tissue organizers, orienting and ordering collagen fibrils during ontogeny and are involved in pathological processes such as wound healing, tissue repair, and tumor stroma formation. Iozzo, R. V., Crit. Rev. Biochem. Mol. Biol., 32(2):141–174 (1997). Others studies implicating leucine rich proteins in wound healing and tissue repair are De La Salle, C., et al., Vouv. Rev. Fr. Hematol. (Germany), 37(4):215–222 (1995), reporting mutations in the leucine rich motif in a complex associated with the bleeding disorder Bernard-Soulier syndrome, Chlemetson, K. J., Thromb. Haemost. (Germany), 74(1):111–116 (July 1995), reporting that platelets have leucine rich repeats and Ruoslahti, E. I., et al., WO9110727-A by La Jolla Cancer Research Foundation reporting that decorin binding to transforming growth factors has involvement in a treatment for cancer, wound healing and scarring. Related by function to this group of proteins is the insulin like growth factor (IGF), in that it is useful in wound-healing and associated therapies concerned with re-growth of tissue, such as connective tissue, skin and bone; in promoting body growth in humans and animals; and in stimulating other growth-related processes. The acid labile subunit (ALS) of IGF is also of interest in that it increases the half-life of IGF and is part of the IGF complex in vivo. ALS is further described in Leong and Baxter, Mol. Endocrinol., 6(6):870–876 (1992); Baxter, J. Biol. Chem., 264(20):11843–11848 (1989); and Khosravi, et al., J. Clin. Endocrinol. Metab., 82(12):3944–3951 (1997).
Another protein which has been reported to have leucine-rich repeats is the SLIT protein which has been reported to be useful in treating neuro-degenerative diseases such as Alzheimer's disease, nerve damage such as in Parkinson's disease, and for diagnosis of cancer, see, Artavanistsakonas, S. and Rothberg, J. M., WO9210518-A1 by Yale University. Also of interest is LIG-1, a membrane glycoprotein that is expressed specifically in glial cells in the mouse brain, and has leucine rich repeats and immunoglobulin-like domains. Suzuki, et al., J. Biol. Chem. (U.S.), 271(37):22522 (1996). Other studies reporting on the biological functions of proteins having leucine rich repeats include: Tayar, N., et al., Mol. Cell Endocrinol., (Ireland), 125(1–2):65–70 (December 1996) (gonadotropin receptor involvement); Miura, Y., et al., Nippon Rinsho (Japan), 54(7):1784–1789 (July 1996) (apoptosis involvement); Harris, P. C., et al., J. Am. Soc. Nephrol., 6(4):1125–1133 (October 1995) (kidney disease involvement).
Efforts are therefore being undertaken by both industry and academia to identify new proteins having leucine rich repeats to better understand protein-protein interactions. Of particular interest are those proteins having leucine rich repeats and identity or similarity to known proteins having leucine rich repeats such as ALS. Many efforts are focused on the screening of mammalian recombinant DNA libraries to identify the coding sequences for novel secreted and membrane-bound proteins having leucine rich repeats. Examples of screening methods and techniques are described in the literature [see, for example, Klein et al., Proc. Natl. Acad. Sci., 93:7108–7113 (1996); U.S. Pat. No. 5,536,637)].
62. PRO531
Cadherins are a large family of transmembrane proteins. Cadherins comprise a family of calcium-dependent glycoproteins that function in mediating cell-cell adhesion in virtually all solid tissues of multicellular organisms. At least cadherins 1–13 as well as types B, E, EP, M, N, P and R have been characterized. Among the functions cadherins are known for, with some exceptions, cadherins participate in cell aggregation and are associated with cell-cell adhesion sites. Recently, it has been reported that while all cadherins share multiple repeats of a cadherin specific motif believed to correspond to folding of extracellular domains, members of the cadherin superfamily have divergent structures and, possibly, functions. In particular it has been reported that members of the cadherin superfamily are involved in signal transduction. See, Suzuki, J. Cell Biochem., 61(4):531–542 (1996). Cadherins are further described in Tanihara, et al., J. Cell Sci., 107(6):1697–1704 (1994), Aberle, et al., J. Cell Biochem., 61(4):514–523 (1996) and Tanihara, et al., Cell Adhes. Commun., 2(1):15–26 (1994).
Protocadherins are members of the cadherin superfamily which are highly expressed in the brain. In some studies, protocadherins have shown cell adhesion activity. See, Sano, et al., EMBO J., 12(6):2249–2256 (1993). However, studies have also shown that some protocadherins, such as protocadherin 3 (also referred to as Pcdh3 or pc3), do not show strong calcium dependent cell aggregation activity. See, Sago, et al., Genomics, 29(3):631–640 (1995) for this study and further characteristics of Pcdh3.
Therefore, novel members of the cadherin superfamily are of interest. More generally, all membrane-bound proteins and receptors are of interest. Such proteins can play an important role in the formation, differentiation and maintenance of multicellular organisms. The fate of many individual cells, e.g., proliferation, migration, differentiation, or interaction with other cells, is typically governed by information received from other cells and/or the immediate environment. This information is often transmitted by secreted polypeptides (for instance, mitogenic factors, survival factors, cytotoxic factors, differentiation factors, neuropeptides, and hormones) which are, in turn, received and interpreted by diverse cell receptors or membrane-bound proteins. Such membrane-bound proteins and cell receptors include, but are not limited to, cytokine receptors, receptor kinases, receptor phosphatases, receptors involved in cell-cell interactions, and cellular adhesin molecules like selectins and integrins. For instance, transduction of signals that regulate cell growth and differentiation is regulated in part by phosphorylation of various, cellular proteins. Protein tyrosine kinases, enzymes that catalyze that process, can also act as growth factor receptors. Examples include fibroblast growth factor receptor and nerve growth factor receptor.
Membrane-bound proteins and receptor molecules have various industrial applications, including as pharmaceutical and diagnostic agents. Receptor immunoadhesins, for instance, can be employed as therapeutic agents to block receptor-ligand interaction. The membrane-bound proteins can also be employed for screening of potential peptide or small molecule inhibitors of the relevant receptor/ligand interaction.
Efforts are therefore being undertaken by both industry and academia to identify new, native membrane bound proteins, particular those having sequence identity with protocadherins, especially 3 and 4. Many efforts are focused on the screening of mammalian recombinant DNA libraries to identify the coding sequences for novel membrane-bound proteins. Provided herein are the results of such efforts.
63. PRO534
Protein disulfide isomerase is an enzymatic protein which is involved in the promotion of correct refolding of proteins through the establishment of correct disulfide bond formation. Protein disulfide isomerase was initially identified based upon its ability to catalyze the renaturation of reduced denatured RNAse (Goldberger et al., J. Biol. Chem. 239:1406–1410 (1964) and Epstein et al., Cold Spring Harbor Symp. Quant. Biol. 28:439–449 (1963)). Protein disulfide isomerase has been shown to be a resident enzyme of the endoplasmic reticulum which is retained in the endoplasmic reticulum via a -KDEL or -HDEL amino acid sequence at its C-terminus. Protein disulfide isomerase and related proteins are further described in Laboissiere, et al., J. Biol. Chem., 270(47:28006–28009 (1995); Jeenes, et al., Gene, 193(2):151–156 (1997; Koivan, et al., Genomics, 42(3):397–404 (1997); and Desilva, et al., DNA Cell Biol., 15(1):9–16 (1996). These studies indicate the importance of the identification of protein disulfide related proteins.
More generally, and also of interest are all novel membrane-bound proteins and receptors. Such proteins can play an important role in the formation, differentiation and maintenance of multicellular organisms. The fate of many individual cells, e.g., proliferation, migration, differentiation, or interaction with other cells, is typically governed by information received from other cells and/or the immediate environment. This information is often transmitted by secreted polypeptides (for instance, mitogenic factors, survival factors, cytotoxic factors, differentiation factors, neuropeptides, and hormones) which are, in turn, received and interpreted by diverse cell receptors or membrane-bound proteins. Such membrane-bound proteins and cell receptors include, but are not limited to, cytokine receptors, receptor kinases, receptor phosphatases, receptors involved in cell-cell interactions, and cellular adhesin molecules like selectins and integrins. For instance, transduction of signals that regulate cell growth and differentiation is regulated in part by phosphorylation of various cellular proteins. Protein tyrosine kinases, enzymes that catalyze that process, can also act as growth factor receptors. Examples include fibroblast growth factor receptor and nerve growth factor receptor.
Membrane-bound proteins and receptor molecules have various industrial applications, including as pharmaceutical and diagnostic agents. Receptor immunoadhesins, for instance, can be employed as therapeutic agents to block receptor-ligand interaction. The membrane-bound proteins can also be employed for screening of potential peptide or small molecule inhibitors of the relevant receptor/ligand interaction.
Given the importance of membrane bound proteins, efforts are under way to identity novel membrane bound proteins. Moreover, given the importance of disulfide bond-forming enzymes and their potential uses in a number of different applications, for example in increasing the yield of correct refolding of recombinantly produced proteins, efforts are currently being undertaken by both industry and academia to identify new, native proteins having sequence identity with protein disulfide isomerase. Many of these efforts are focused on the screening of mammalian recombinant DNA libraries to identify the coding sequences for novel protein disulfide isomerase homologs. We herein describe a novel polypeptide having sequence identity with protein disulfide isomerase and the nucleic acids encoding the same.
64. PRO697
Secreted fizzled related proteins (sFRPs) are related to the frizzled family of transmembrane receptors. The sFRPs are approximately 30 kDa in size, and each contains a putative signal sequence, a frizzled-like cysteine-rich domain, and a conserved hydrophilic carboxy-terminal domain. It has been reported that sFRPs may function to modulate Wnt signaling, or function as ligands for certain receptors. Rattner, et al., PNAS USA, 94(7):2859–2863 (1997). Therefore, sFRPs and proteins having sequence identity and/or similarity to sFRPs are of interest.
Another secreted protein of interest is any member of the family of secreted apoptosis-related proteins (SARPs). Expression of SARPs modifies the intracellular levels of beta-catenin, suggesting that SARPs interfere with the Wnt-frizzled proteins signaling pathway. Melkonyan, et al., PNAS USA, 94(25):13636–13641 (1997). Therefore, SARPs and proteins having sequence identity and/or similarity to SARPs are of interest.
In addition to sFRPs and SARPs, many extracellular proteins are of interest. Extracellular proteins play an important role in the formation, differentiation and maintenance of multicellular organisms. The fate of many individual cells, e.g., proliferation, migration, differentiation, or interaction with other cells, is typically governed by information received from other cells and/or the immediate environment. This information is often transmitted by secreted polypeptides (for instance, mitogenic factors, survival factors, cytotoxic factors, differentiation factors, neuropeptides, and hormones) which are, in turn, received and interpreted by diverse cell receptors or membrane-bound proteins. These secreted polypeptides or signaling molecules normally pass through the cellular secretory pathway to reach their site of action in the extracellular environment.
Secreted proteins have various industrial applications, including pharmaceuticals, diagnostics, biosensors and bioreactors. Most protein drugs available at present, such as thrombolytic agents, interferons, interleukins, erythropoietins, colony stimulating factors, and various other cytokines, are secretory proteins. Their receptors, which are membrane proteins, also have potential as therapeutic or diagnostic agents.
Efforts are being undertaken by both industry and academia to identify new, native secreted proteins, particularly those having sequence identity or similarity with sFRP-2 and SARP-1. Many efforts are focused on the screening of mammalian recombinant DNA libraries to identify the coding sequences for novel secreted proteins. Examples of screening methods and techniques are described in the literature [see, for example, Klein et al., Proc. Natl. Acad. Sci., 93:7108–7113 (1996); U.S. Pat. No. 5,536,637)].
65. PRO717
Efforts are being undertaken by both industry and academia to identify new, native transmembrane receptor proteins. Many efforts are focused on the screening of mammalian recombinant DNA libraries to identify the coding sequences for novel receptor proteins. The results of such efforts are provided herein.
66. PRO731
Cadherins are a large family of transmembrane proteins. Cadherins comprise a family of calcium-dependent glycoproteins that function in mediating cell-cell adhesion in virtually all solid tissues of multicellular organisms. At least cadherins 1–13 as well as types B, E, EP, M, N, P and R have been characterized. Among the functions cadherins are known for, with some exceptions, cadherins participate in cell aggregation and are associated with cell-cell adhesion sites. Recently, it has been reported that while all cadherins share multiple repeats of a cadherin specific motif believed to correspond to folding of extracellular domains, members of the cadherin superfamily have divergent structures and, possibly, functions. In particular it has been reported that members of the cadherin superfamily are involved in signal transduction. See, Suzuki, J. Cell Biochem. 61(4):531–542 (1996). Cadherins are further described in Tanihara, et al., J. Cell Sci., 107(6):1697–1704 (1994), Aberle, et al., J. Cell Biochem., 61(4):514–523 (1996) and Tanihara, et al., Cell Adhes. Commun., 2(1):15–26 (1994).
Protocadherins are members of the cadherin superfamily which are highly expressed in the brain. In some studies, protocadherins have shown cell adhesion activity. See, Sano, et al., EMBO J., 12(6):2249–2256 (1993). However, studies have also shown that some protocadherins, such as protocadherin 3 (also referred to as Pcdh3 or pc3), do not show strong calcium dependent cell aggregation activity. See, Sago, et al., Genomics, 29(3):631–640 (1995) for this study and further characteristics of Pcdh3.
Therefore, novel members of the cadherin superfamily are of interest. More generally, all membrane-bound proteins and receptors are of interest. Such proteins can play an important role in the formation, differentiation and maintenance of multicellular organisms. The fate of many individual cells, e.g., proliferation, migration, differentiation, or interaction with other cells, is typically governed by information received from other cells and/or the immediate environment. This information is often transmitted by secreted polypeptides (for instance, mitogenic factors, survival factors, cytotoxic factors, differentiation factors, neuropeptides, and hormones) which are, in turn, received and interpreted by diverse cell receptors or membrane-bound proteins. Such membrane-bound proteins and cell receptors include, but are not limited to, cytokine receptors, receptor kinases, receptor phosphatases, receptors involved in cell-cell interactions, and cellular adhesin molecules like selectins and integrins. For instance, transduction of signals that regulate cell growth and differentiation is regulated in part by phosphorylation of various cellular proteins. Protein tyrosine kinases, enzymes that catalyze that process, can also act as growth factor receptors. Examples include fibroblast growth factor receptor and nerve growth factor receptor.
Membrane-bound proteins and receptor molecules have various industrial applications, including as pharmaceutical and diagnostic agents. Receptor immunoadhesins, for instance, can be employed as therapeutic agents to block receptor-ligand interaction. The membrane-bound proteins can also be employed for screening of potential peptide or small molecule inhibitors of the relevant receptor/ligand interaction.
Efforts are therefore being undertaken by both industry and academia to identify new, native membrane bound proteins, particular those having sequence identity with protocadherins, especially 4, 68, 43, 42, 3 and 5. Many efforts are focused on the screening of mammalian recombinant DNA libraries to identify the coding sequences for novel membrane-bound proteins. Provided herein are the results of such efforts.
67. PRO218
Efforts are being undertaken by both industry and academia to identify new, native membrane bound proteins, particularly those having sequence identity with membrane regulator proteins. Many efforts are focused on the screening of mammalian recombinant DNA libraries to identify the coding sequences for novel receptor proteins.
68. PRO768
The integrins comprise a supergene family of cell-surface glycoprotein receptors that promote cellular adhesion. Each cell has numerous receptors that define its cell adhesive capabilities. Integrins are involved in a wide variety of interaction between cells and other cells or matrix components. The integrins are of particular importance in regulating movement and function of immune system cells. The platelet IIb/IIIA integrin complex is of particular importance in regulating platelet aggregation. A member of the integrin family, integrin β-6, is expressed on epithelial cells and modulates epithelial inflammation. Another integrin, leucocyte-associated antigen-1 (FLA-1) is important in the adhesion of lymphocytes during an immune response.
Of particular interest is H36-alpha 7, an integrin alpha chain that is developmentally regulated during myogenesis as described in Song, et al., J. Cell Biol., 117(3):643–657 (1992). The expression pattern of the laminin-binding alpha 7 beta 1 integrin is developmentally regulated in skeletal, cardiac, and smooth muscle. Ziober, et al., Mol. Biol. Cell, 8(9):1723–1734 (1997). It has been reported that expression of the alpha 7-X1/X2 integrin is a novel mechanism that regulates receptor affinity states in a cell-specific context and may modulate integrin-dependent events during muscle development and repair. Id. It has further been reported that laminins promote the locomotion of skeletal myoblasts via the alpha 7 integrin receptor. In particular it was reported that alpha 7 beta 1 receptor can promote myoblast adhesion and motility on a restricted number of laminin isoforms and may be important in myogenic precursor recruitment during regeneration and differentiation. Yao, et al., J. Cell Sci., 109(13):3139–3150 (1996). Spliced variants of integrin alpha 7 are also described in Leung, et al., Biochem. Biophys. Res. Commun., 243(1):317–325 (1998) and Fornaro and Languino, Matrix Biol., 16(4):185–193 (1997). Moreover, it has been reported that absence of integrin alpha 7 causes a form of muscular dystrophy. Thus integrins, particularly those related to integrin 7 and related molecules, are of interest.
In addition to the interest of integrins, more generally, all membrane-bound proteins and receptors are of interest since such proteins can play an important role in the formation, differentiation and maintenance of multicellular organisms. The fate of many individual cells, e.g., proliferation, migration, differentiation, or interaction with other cells, is typically governed by information received from other cells and/or the immediate environment. This information is often transmitted by secreted polypeptides (for instance, mitogenic factors, survival factors, cytotoxic factors, differentiation factors, neuropeptides, and hormones) which are, in turn, received and interpreted by diverse cell receptors or membrane-bound proteins. Such membrane-bound proteins and cell receptors include, but are not limited to, cytokine receptors, receptor kinases, receptor phosphatases, receptors involved in cell-cell interactions, and cellular adhesin molecules like selectins and integrins. For instance, transduction of signals that regulate cell growth and differentiation is regulated in part by phosphorylation of various cellular proteins. Protein tyrosine kinases, enzymes that catalyze that process, can also act as growth factor receptors. Examples include fibroblast growth factor receptor and nerve growth factor receptor.
Membrane-bound proteins and receptor molecules have various industrial applications, including as pharmaceutical and diagnostic agents. Receptor immunoadhesins, for instance, can be employed as therapeutic agents to block receptor-ligand interaction. The membrane-bound proteins can also be employed for screening of potential peptide or small molecule inhibitors of the relevant receptor/ligand interaction.
Therefore, efforts are being undertaken by both industry and academia to identify new, native receptor proteins. Many efforts are focused on the screening of mammalian recombinant DNA libraries to identify the coding sequences for novel receptor proteins. The results of such efforts, particularly those focused on identifying new polypeptides having sequence identity with integrins, are provided herein.
69. PRO771
Testican is a multidomain testicular proteoglycan which is expressed in numerous tissue types including, but not limited to neuromuscular tissue, the brain and reproductive tissues. Testican resembles modulators of cell social behavior such as the regulation of cell shape, adhesion, migration and proliferation. [Bonnet, F. et al., J. Biol. Chem., 271(8):4373 (1996), Perin, J. P. et al., EXS (Switzerland), 70:191 (1994), Alliel, P. M. et al, Eur. J. Biochem., 214(1):346 (1993), Charbonnier, F., et al., C. R. Seances Soc. Biol. Fil. (France), 191(1):127 (1997)]. Among other reasons, since testican has been implicated in neuronal processes and may be associated with the growth of connective tissue, testican and related molecules are of interest.
More generally, all extracellular proteins are of interest. Extracellular proteins play an important role in the formation, differentiation and maintenance of multicellular organisms. The fate of many individual cells, e.g., proliferation, migration, differentiation, or interaction with other cells, is typically governed by information received from other cells and/or the immediate environment. This information is often transmitted by secreted polypeptides (for instance, mitogenic factors, survival factors, cytotoxic factors, differentiation factors, neuropeptides, and hormones) which are, in turn, received and interpreted by diverse cell receptors or membrane-bound proteins. These secreted polypeptides or signaling molecules normally pass through the cellular secretory pathway to reach their site of action in the extracellular environment.
Secreted proteins have various industrial applications, including pharmaceuticals, diagnostics, biosensors and bioreactors. Most protein drugs available at present, such as thrombolytic agents, interferons, interleukins, erythropoietins, colony stimulating factors, and various other cytokines, are secretory proteins. Their receptors, which are membrane proteins, also have potential as therapeutic or diagnostic agents. Efforts are being undertaken by both industry and academia to identify new, native secreted proteins. Many efforts are focused on the screening of mammalian recombinant DNA libraries to identify the coding sequences for novel secreted proteins. Examples of screening methods and techniques are described in the literature [see, for example, Klein et al., Proc. Natl. Acad. Sci., 93:7108–7113 (1996); U.S. Pat. No. 5,536,637)]. The results of such efforts, particularly those focused on identifying molecules having identity and/or similarity with testican are of interest.
70. PRO733
T1/ST2 is a receptor-like molecule homologous to the type I interleukin-1 receptor, believed to be involved in cell signaling. The T1/ST2 receptor and/or putative ligands are further described in Gayle, et al., J. Biol. Chem., 271(10):5784–5789 (1996), Kumar, et al., J. Biol. Chem., 270(46):27905–27913 (1995), and Mitcham, et al., J. Biol. Chem., 271(10):5777–5783 (1996). These proteins, and proteins related thereto are of interest.
More generally all membrane-bound proteins and receptors are of interest since they can play an important role in the formation, differentiation and maintenance of multicellular organisms. The fate of many individual cells, e.g., proliferation, migration, differentiation, or interaction with other cells, is typically governed by information received from other cells and/or the immediate environment. This information is often transmitted by secreted polypeptides (for instance, mitogenic factors, survival factors, cytotoxic factors, differentiation factors, neuropeptides, and hormones) which are, in turn, received and interpreted by diverse cell receptors or membrane-bound proteins. Such membrane-bound proteins and cell receptors include, but are not limited to, cytokine receptors, receptor kinases, receptor phosphatases, receptors involved in cell-cell interactions, and cellular adhesin molecules like selectins and integrins. For instance, transduction of signals that regulate cell growth and differentiation is regulated in part by phosphorylation of various cellular proteins. Protein tyrosine kinases, enzymes that catalyze that process, can also act as growth factor receptors. Examples include fibroblast growth factor receptor and nerve growth factor receptor.
Membrane-bound proteins and receptor molecules have various industrial applications, including as pharmaceutical and diagnostic agents. Receptor immunoadhesins, for instance, can be employed as therapeutic agents to block receptor-ligand interaction. The membrane-bound proteins can also be employed for screening of potential peptide or small molecule inhibitors of the relevant receptor/ligand interaction.
Efforts are being undertaken by both industry and academia to identify new, native receptor proteins. Many efforts are focused on the screening of mammalian recombinant DNA libraries to identify the coding sequences for novel receptor proteins. The results of such efforts are provided herein.
71. PRO162
Pancreatitis-associated protein (PAP) is a secretory protein that is overexpressed by the pancreas during acute pancreatitis. Serum PAP concentrations have been shown to be abnormally high in patients with acute pancreatitis. Pezzilli et al., Am. J. Gastroenterol., 92(10):1887–1890 (1997).
PAP is synthesized by the pancreas due to pancreatic inflammation and has been shown to be a good serum marker for injury of the pancreas. In addition, serum PAP levels appear to strongly correlate with creatinine clearance measurements. In patients with a pancreas-kidney transplantation, PAP may prove to be a useful biological and histological marker of pancreatic graft rejection. Van der Pijl et al., Transplantation, 63(7):995–1003 (1997). Further, PAP has been shown to be useful in screening neonates for cystic fibrosis. In fact, PAP may discriminate cystic fibrosis neonates with better specificity than the current immunoreactive trypsis assay. Iovanna et al., C. R. Acad. Aci. III, 317(6):561–564.
Secreted proteins such as PAP have various industrial applications, including pharmaceuticals, diagnostics, biosensors and bioreactors. Most protein drugs available at present, such as thrombolytic agents, interferons, interleukins, erythropoietins, colony stimulating factors, and various other cytokines, are secretory proteins. Their receptors, which are membrane proteins, also have potential as therapeutic or diagnostic agents.
Efforts are being undertaken by both industry and academia to identify new, native secreted proteins. Many efforts are focused on the screening of mammalian recombinant DNA libraries to identify the coding sequences for novel secreted proteins. Examples of screening methods and techniques are described in the literature [see, for example, Klein et al., Proc. Natl. Acad. Sci., 93:7108–7113 (1996); U.S. Pat. No. 5,536,637)]. The results of such efforts are presented herein.
72. PRO788
Anti-neoplastic urinary protein (ANUP) was identified as the major protein present in a fraction of human urine which exhibits antiproliferative activity against human tumor cell lines without affecting the growth of several normal diploid cell lines or tumor cells of mouse or hamster origin. Sloane et al., Biochem. J., 234(2):355–362 (1986).
ANUP is a unique cytokine that has been found in human granulocytes. The N-terminal amino acid sequence has been shown to be unique. A synthetic peptide corresponding to the first nine residues, with Cys at positions 4 and 7, was found to be an anti-tumor agent in vitro. Ridge and Sloane, Cytokine, 8(1):1–5 (1996).
Secreted proteins such as ANUP have various industrial applications, including pharmaceuticals, diagnostics, biosensors and bioreactors. Most protein drugs available at present, such as thrombolytic agents, interferons, interleukins, erythropoietins, colony stimulating factors, and various other cytokines, are secretory proteins. Their receptors, which are membrane proteins, also have potential as therapeutic or diagnostic agents. Efforts are being undertaken by both industry and academia to identify new, native secreted proteins. Many efforts are focused on the screening of mammalian recombinant DNA libraries to identify the coding sequences for novel secreted proteins. Examples of screening methods and techniques are described in the literature [see, for example, Klein et al., Proc. Natl. Acad. Sci., 93:7108–7113 (1996); U.S. Pat. No. 5,536,637)].
73. PRO1008
Dickkopf-1 (dkk-1) is a member of a family of secreted proteins and functions in head induction. Dkk-1 is an inducer of Spemann organizer in amphibian embryos. Glinka, et al., Nature, 391(6665):357–362 (1998). Dkk-1 is a potent antagonist of Wnt signalling, suggesting that dkk genes encode a family of secreted Wnt inhibitors. Thus, dkk-1 family members and related molecules are of interest.
More generally, all extracellular proteins are of interest since they can play an important role in the formation, differentiation and maintenance of multicellular organisms. The fate of many individual cells, e.g., proliferation, migration, differentiation, or interaction with other cells, is typically governed by information received from other cells and/or the immediate environment. This information is often transmitted by secreted polypeptides (for instance, mitogenic factors, survival factors, cytotoxic factors, differentiation factors, neuropeptides, and hormones) which are, in turn, received and interpreted by diverse cell receptors or membrane-bound proteins. These secreted polypeptides or signaling molecules normally pass through the cellular secretory pathway to reach their site of action in the extracellular environment.
Secreted proteins have various industrial applications, including pharmaceuticals, diagnostics, biosensors and bioreactors. Most protein drugs available at present, such as thrombolytic agents, interferons, interleukins, erythropoietins, colony stimulating factors, and various other cytokines, are secretory proteins. Their receptors, which are membrane proteins, also have potential as therapeutic or diagnostic agents.
Efforts are being undertaken by both industry and academia to identify new, native secreted proteins, particularly those related to dkk-1. Many efforts are focused on the screening of mammalian recombinant DNA libraries to identify the coding sequences for novel secreted proteins. Examples of screening methods and techniques are described in the literature [see, for example, Klein et al., Proc. Natl. Acad. Sci., 93:7108–7113 (1996); U.S. Pat. No. 5,536,637)]. The results of such efforts to identify molecules related to dkk-1 are provided herein.
74. PRO1012
Protein disulfide isomerase is an enzymatic protein which is involved in the promotion of correct refolding of proteins through the establishment of correct disulfide bond formation. Protein disulfide isomerase was initially identified based upon its ability to catalyze the renaturation of reduced denatured RNAse (Goldberger et al., J. Biol. Chem. 239:1406–1410 (1964) and Epstein et al., Cold Spring Harbor Symp. Quant. Biol. 28:439–449 (1963)). Protein disulfide isomerase has been shown to be a resident enzyme of the endoplasmic reticulum which is retained in the endoplasmic reticulum via a -KDEL or -HDEL amino acid sequence at its C-terminus. Protein disulfide isomerase and related proteins are further described in Laboissiere, et al., J. Biol. Chem., 270(47:28006–28009 (1995); Jeenes, et al., Gene, 193(2):151–156 (1997; Koivunen, et al., Genomics, 42(3):397–404 (1997); and Desilva, et al., DNA Cell Biol., 15(1):9–16 (1996). These studies indicate the importance of the identification of protein disulfide related proteins.
More generally, the identification of all extracellular and membrane-bound proteins is of interest since they play important roles in the formation, differentiation and maintenance of multicellular organisms. The fate of many individual cells, e.g., proliferation, migration, differentiation, or interaction with other cells, is typically governed by information received from other cells and/or the immediate environment. This information is often transmitted by secreted polypeptides (for instance, mitogenic factors, survival factors, cytotoxic factors, differentiation factors, neuropeptides, and hormones) which are, in turn, received and interpreted by diverse cell receptors or membrane-bound proteins. These secreted polypeptides or signaling molecules normally pass through the cellular secretory pathway to reach their site of action in the extracellular environment, usually at a membrane-bound receptor protein.
Secreted proteins have various industrial applications, including use as pharmaceuticals, diagnostics, biosensors and bioreactors. In fact, most protein drugs available at present, such as thrombolytic agents, interferons, interleukins, erythropoietins, colony stimulating factors, and various other cytokines, are secretory proteins. Their receptors, which are membrane-bound proteins, also have potential as therapeutic or diagnostic agents. Receptor immunoadhesins, for instance, can be employed as therapeutic agents to block receptor-ligand interaction. Membrane-bound proteins can also be employed for screening of potential peptide or small molecule inhibitors of the relevant receptor/ligand interaction. Such membrane-bound proteins and cell receptors include, but are not limited to, cytokine receptors, receptor kinases, receptor phosphatases, receptors involved in cell-cell interactions, and cellular adhesin molecules like selectins and integrins. Transduction of signals that regulate cell growth and differentiation is regulated in part by phosphorylation of various cellular proteins. Protein tyrosine kinases, enzymes that catalyze that process, can also act as growth factor receptors. Examples include fibroblast growth factor receptor and nerve growth factor receptor.
Of particular interest are cellular proteins having endoplasmic reticulum (ER) retention signals. These proteins are retained in the cell and function closely with endoplasmic reticulum in protein production. Such proteins have been described previously, i.e., see Shorrosh and Dixon, Plant J., 2(1):51–58 (1992).
Efforts are being undertaken by both industry and academia to identify new, native secreted and membrane-bound receptor proteins, and in particular, cellular proteins having ER retension signals. Many efforts are focused on the screening of mammalian recombinant DNA libraries to identify the coding sequences for novel secreted and membrane-bound receptor proteins. Examples of screening methods and techniques are described in the literature [see, for example, Klein et al., Proc. Natl. Acad. Sci., 93:7108–7113 (1996); U.S. Pat. No. 5,536,637)]. The results of such efforts, particularly the identification of novel polypeptides and nucleic acids encoding the same, which have sequence identity and similarity to protein disulfide isomerase are presented herein.
75. PRO1014
Oxygen free radicals and antioxidants appear to play an important role in the central nervous system after cerebral ischemia and reperfusion. Moreover, cardiac injury, related to ischaemia and reperfusion has been reported to be caused by the action of free radicals. Additionally, studies have reported that the redox state of the cell is a pivotal determinant of the fate of the cells. Furthermore, reactive oxygen species have been reported to be cytotoxic, causing inflammatory disease, including tissue necrosis, organ failure, atherosclerosis, infertility, birth defects, premature aging, mutations and malignancy. Thus, the control of oxidation and reduction is important for a number of reasons including for control and prevention of strokes, heart attacks, oxidative stress and hypertension. In this regard, reductases, and particularly, oxidoreductases, are of interest. Publications further describing this subject matter include Kelsey, et al., Br. J. Cancer, 76(7):8524 (1997); Friedrich and Weiss, J. Theor. Biol., 187(4):529–40 (1997) and Pieulle, et al., J. Bacteriol., 179(18):5684–92 (1997).
In addition to reductases in particular, novel polypeptides are generally of interest. Extracellular proteins play an important role in the formation, differentiation and maintenance of multicellular organisms. The fate of many individual cells, e.g., proliferation, migration, differentiation, or interaction with other cells, is typically governed by information received from other cells and/or the immediate environment. This information is often transmitted by secreted polypeptides (for instance, mitogenic factors, survival factors, cytotoxic factors, differentiation factors, neuropeptides, and hormones) which are, in turn, received and interpreted by diverse cell receptors or membrane-bound proteins. These secreted polypeptides or signaling molecules normally pass through the cellular secretory pathway to reach their site of action in the extracellular environment.
Secreted proteins have various industrial applications, including pharmaceuticals, diagnostics, biosensors and bioreactors. Most protein drugs available at present, such as thrombolytic agents, interferons, interleukins, erythropoietins, colony stimulating factors, and various other cytokines, are secretory proteins. Their receptors, which are membrane proteins, also have potential as therapeutic or diagnostic agents. Efforts are being undertaken by both industry and academia to identify new, native secreted proteins. Many efforts are focused on the screening of mammalian recombinant. DNA libraries to identify the coding sequences for novel secreted proteins. Examples of screening methods and techniques are described in the literature [see, for example, Klein et al., Proc. Natl. Acad. Sci., 93:7108–7113 (1996); U.S. Pat. No. 5,536,637)]. The results of such efforts, particularly those identifying polypeptides having sequence identity with reductases, and the nucleic acids encoding the same, are presented herein.
76. PRO1017
Enzymatic proteins play important roles in the chemical reactions involved in the digestion of foods, the biosynthesis of macromolecules, the controlled release and utilization of chemical energy, and other processes necessary to sustain life. Sulfotransferases are enzymes which transfer sulfate from a sulfate donor to acceptor substrates, particularly those containing terminal glucoronic acid. The HNK-1 carbohydrate epitope is expressed on several neural adhesion glycoproteins and a glycolipid, and is involved in cell interactions. The glucuronyltransferase and sulfotransferase are considered to be the key enzymes in the biosynthesis of this epitope because the rest of the structure occurs often in glycoconjugates. HNK-1 sulfotransfererase is further described in Bakker, H., et al., J. Biol. Chem., 272(47):29942–29946 (1997).
In addition to HNK-1 sulfotransfererase, and novel proteins related thereto, all novel proteins are of interest. Extracellular and membrane-bound proteins play important roles in the formation, differentiation and maintenance of multicellular organisms. The fate of many individual cells, e.g., proliferation, migration, differentiation, or interaction with other cells, is typically governed by information received from other cells and/or the immediate environment. This information is often transmitted by secreted polypeptides (for instance, mitogenic factors, survival factors, cytotoxic factors, differentiation factors, neuropeptides, and hormones) which are, in turn, received and interpreted by diverse cell receptors or membrane-bound proteins. These secreted polypeptides or signaling molecules normally pass through the cellular secretory pathway to reach their site of action in the extracellular environment, usually at a membrane-bound receptor protein.
Secreted proteins have various industrial applications, including use as pharmaceuticals, diagnostics, biosensors and bioreactors. In fact, most protein drugs available at present, such as thrombolytic agents, interferons, interleukins, erythropoietins, colony stimulating factors, and various other cytokines, are secretory proteins. Their receptors, which are membrane-bound proteins, also have potential as therapeutic or diagnostic agents. Receptor immunoadhesins, for instance, can be employed as therapeutic agents to block receptor-ligand interaction. Membrane-bound proteins can also be employed for screening of potential peptide or small molecule inhibitors of the relevant receptor/ligand interaction. Such membrane-bound proteins and cell receptors include, but are not limited to, cytokine receptors, receptor kinases, receptor phosphatases, receptors involved in cell-cell interactions, and cellular adhesin molecules like selectins and integrins. Transduction of signals that regulate cell growth and differentiation is regulated in part by phosphorylation of various cellular proteins. Protein tyrosine kinases, enzymes that catalyze that process, can also act as growth factor receptors. Examples include fibroblast growth factor receptor and nerve growth factor receptor.
Efforts are being undertaken by both industry and academia to identify new, native secreted and membrane-bound receptor proteins, particularly those having sequence identity with HNK-1 sulfotransferase. Many efforts are focused on the screening of mammalian recombinant DNA libraries to identify the coding sequences for novel secreted and membrane-bound receptor proteins. Examples of screening methods and techniques are described in the literature [see, for example,. Klein et al., Proc. Natl. Acad. Sci., 93:7108–7113 (1996); U.S. Pat. No. 5,536,637)]. The results of such efforts are provided herein.
77. PRO474
Enzymatic proteins play important roles in the chemical reactions involved in the digestion of foods, the biosynthesis of macromolecules, the controlled release and utilization of chemical energy, and other processes necessary to sustain life. Glucose dehydrogenase functions in the oxidation of glucose to gluconate to generate metabolically useful energy. The regulation of the PQQ-linked glucose dehydrogenase in different organisms is reviewed in Neijssel, et al., Antonie Van Leeuwenhoek, 56(1):51–61 (1989). Glucose dehydrogenase functions as an auxiliary energy generating mechanism, because it is maximally synthesized under conditions of energy stress. In addition to molecules related to glucose dehydrogenase, all novel proteins are of interest. Extracellular and membrane-bound proteins play important roles in the formation, differentiation and maintenance of multicellular organisms. The fate of many individual cells, e.g., proliferation, migration, differentiation, or interaction with other cells, is typically governed by information received from other cells and/or the immediate environment. This information is often transmitted by secreted polypeptides (for instance, mitogenic factors, survival factors, cytotoxic factors, differentiation factors, neuropeptides, and hormones) which are, in turn, received and interpreted by diverse cell receptors or membrane-bound proteins. These secreted polypeptides or signaling molecules normally pass through the cellular secretory pathway to reach their site of action in the extracellular environment, usually at a membrane-bound receptor protein.
Secreted proteins have various industrial applications, including use as pharmaceuticals, diagnostics, biosensors and bioreactors. In fact, most protein drugs available at present, such as thrombolytic agents, interferons, interleukins, erythropoietins, colony stimulating factors, and various other cytokines, are secretory proteins. Their receptors, which are membrane-bound proteins, also have potential as therapeutic or diagnostic agents. Receptor immunoadhesins, for instance, can be employed as therapeutic agents to block receptor-ligand interaction. Membrane-bound proteins can also be employed for screening of potential peptide or small molecule inhibitors of the relevant receptor/ligand interaction. Such membrane-bound proteins and cell receptors include, but are not limited to, cytokine receptors, receptor kinases, receptor phosphatases, receptors involved in cell-cell interactions, and cellular adhesin molecules like selectins and integrins. Transduction of signals that regulate cell growth and differentiation is regulated in part by phosphorylation of various cellular proteins. Protein tyrosine kinases, enzymes that catalyze that process, can also act as growth factor receptors. Examples include fibroblast growth factor receptor and nerve: growth factor receptor.
Efforts are being undertaken by both industry and academia to identify new, native secreted and membrane-bound receptor proteins, and particularly cellular proteins and those related to dehydrogenase or oxidoreductase. Many efforts are focused on the screening of mammalian recombinant DNA libraries to identify the coding sequences for novel secreted and membrane-bound receptor proteins. Examples of screening methods and techniques are described in the literature [see, for example, Klein et al., Proc. Natl. Acad. Sci., 93:7108–7113 (1996); U.S. Pat. No. 5,536,637)]. The results of such efforts are presented herein.
78. PRO1031
It has been reported that the cytokine interleukin 17 (IL-17) stimulates epithelial, endothelial, and fibroblastic cells to secrete cytokines such as IL-6, IL-8, and granulocyte-colony-stimulating factor, as well as prostaglandin E2. Moreover, it has been shown that when cultured in the presence of IL-17, fibroblasts could sustain proliferation of CD34+ preferential maturation into neutrophils. Thus it has been suggested that IL-17 constitutes an early initiator of the T cell-dependent inflammatory reaction and/or an element of the cytokine network that bridges the immune system to hematopoiesis. See, Yao, et al., J. Immunol., 155(12):5483–5486 (1995); Fossiez, et al., J. Exp. Med., 183(6):2593–2603 (1996); Kennedy, et al., J. Interferon Cytokine Res., 16(8):611–617 (1996). Thus, proteins related to IL-17 are of interest.
More generally, all novel proteins are of interest. Extracellular proteins play an important role in the formation, differentiation and maintenance of multicellular organisms. The fate of many individual cells, e.g., proliferation, migration, differentiation, or interaction with other cells, is typically governed by information received from other cells and/or the immediate environment. This information is often transmitted by secreted polypeptides (for instance, mitogenic factors, survival factors, cytotoxic factors, differentiation factors, neuropeptides, and hormones) which are, in turn, received and interpreted by diverse cell receptors or membrane-bound proteins. These secreted polypeptides or signaling molecules normally pass through the cellular secretory pathway to reach their site of action in the extracellular environment.
Secreted proteins have various industrial applications, including pharmaceuticals, diagnostics, biosensors and bioreactors. Most protein drugs available at present, such as thrombolytic agents, interferons, interleukins, erythropoietins, colony stimulating factors, and various other cytokines, are secretory proteins. Their receptors, which are membrane proteins, also have potential as therapeutic or diagnostic agents.
Efforts are being undertaken by both industry and academia to identify new, native secreted proteins, particularly those related to IL-17. Many efforts are focused on the screening of mammalian recombinant DNA libraries to identify the coding sequences for novel secreted proteins. Examples of screening methods and techniques are described in the literature [see, for example, Klein et al., Proc. Natl. Acad. Sci., 93:7108–7113 (1996); U.S. Pat. No. 5,536,637)]. The results of such efforts are presented herein.
79. PRO938
Protein disulfide isomerase is an enzymatic protein which is involved in the promotion of correct refolding of proteins through the establishment of correct disulfide bond formation. Protein disulfide isomerase was initially identified based upon its ability to catalyze the renaturation of reduced denatured RNAse (Goldberger et al., J. Biol. Chem. 239:1406–1410 (1964) and Epstein et al., Cold Spring Harbor Symp. Quant. Biol. 28:439–449 (1963)). Protein disulfide isomerase has been shown to be a resident enzyme of the endoplasmic reticulum which is retained in the endoplasmic reticulum via a -KDEL or -HDEL amino acid sequence at its C-terminus. Protein disulfide isomerase and related proteins are further described in Laboissiere, et al., J. Biol. Chem., 270(47):28006–28009 (1995); Jeenes, et al., Gene, 193(2):151–156 (1997); Koivunen, et al., Genomics, 42(3):397–404 (1997); Desilva, et al., DNA Cell Biol., 15(1):9–16 (1996); Freedman, et al. Trends in Biochem. Sci. 19:331–336 (1994); Bulleid, N. J. Advances in Prot. Chem. 44:125–50 (1993); and Noiva, R., Prot. Exp. and Purification 5:1–13 (1994). These studies indicate the importance of the identification of protein disulfide related proteins.
More generally, and also of interest are all novel membrane-bound proteins and receptors. Such proteins can play an important role in the formation, differentiation and maintenance of multicellular organisms. The fate of many individual cells, e.g., proliferation, migration, differentiation, or interaction with other cells, is typically governed by information received from other cells and/or the immediate environment. This information is often transmitted by secreted polypeptides (for instance, mitogenic factors, survival factors, cytotoxic factors, differentiation factors, neuropeptides, and hormones) which are, in turn, received and interpreted by diverse cell receptors or membrane-bound proteins. Such membrane-bound proteins and cell receptors include, but are not limited to, cytokine receptors, receptor kinases, receptor phosphatases, receptors involved in cell-cell interactions, and cellular adhesin molecules like selectins and integrins. For instance, transduction of signals that regulate cell growth and differentiation is regulated in part by phosphorylation of various cellular proteins. Protein tyrosine kinases, enzymes that catalyze that process, can also act as growth factor receptors. Examples include fibroblast growth factor receptor and nerve growth factor receptor.
Membrane-bound proteins and receptor molecules have various industrial applications, including as pharmaceutical and diagnostic agents. Receptor immunoadhesins, for instance, can be employed as therapeutic agents to block receptor-ligand interaction. The membrane-bound proteins can also be employed for screening of potential peptide or small molecule inhibitors of the relevant receptor/ligand interaction.
Given the importance of membrane bound proteins, efforts are under way to identity novel membrane bound proteins. Moreover, given the importance of disulfide bond-forming enzymes and their potential uses in a number of different applications, for example in increasing the yield of correct refolding of recombinantly produced proteins, efforts are currently being undertaken by both industry and academia to identify new, native proteins having sequence identity with protein disulfide isomerase. Many of these efforts are focused on the screening of mammalian recombinant DNA libraries to identify the coding sequences for novel protein disulfide isomerase homologs.
We herein describe the identification and characterization of a novel polypeptide having homology to protein disulfide isomerase.
80. PRO1082
The low density lipoprotein (LDL) receptor is a membrane-bound protein that plays a key role in cholesterol homeostasis, mediating cellular uptake of lipoprotein particles by high affinity binding to its ligands, apolipoprotein (apo) B-100 and apoE. The ligand-binding domain of the LDL receptor contains 7 cysteine-rich repeats of approximately 40 amino acids, wherein each repeat contains 6 cysteines, which form 3 intra-repeat disulfide bonds. These unique structural features provide the LDL receptor with its ability to specifically interact with apo B-100 and apoE, thereby allowing for transport of these lipoprotein particles across cellular membranes and metabolism of their components. Soluble fragments containing the extracellular domain of the LDL receptor have been shown to retain the ability to interact with its specific lipoprotein ligands (Simmons et al., J. Biol. Chem. 272:25531–25536 (1997)). LDL receptors are further described in Javitt, FASEB J., 9(13):1378–1381 (1995) and Herz and Willnow, Ann. NY Acad. Sci., 737:14–19 (1994). Thus, proteins having sequence identity with LDL receptors are of interest.
More generally, all membrane-bound proteins and receptors can play an important role in the formation, differentiation and maintenance of multicellular organisms. The fate of many individual cells, e.g., proliferation, migration, differentiation, or interaction with other cells, is typically governed by information received from other cells and/or the immediate environment. This information is often transmitted by secreted polypeptides (for instance, mitogenic factors, survival factors, cytotoxic factors, differentiation factors, neuropeptides, and hormones) which are, in turn, received and interpreted by diverse cell receptors or membrane-bound proteins. Such membrane-bound proteins and cell receptors include, but are not limited to, cytokine receptors, receptor kinases, receptor phosphatases, receptors involved in cell-cell interactions, and cellular adhesin molecules like selectins and integrins. For instance, transduction of signals that regulate cell growth and differentiation is regulated in part by phosphorylation of various cellular proteins. Protein tyrosine kinases, enzymes that catalyze that process, can also act as growth factor receptors. Examples include fibroblast growth factor receptor and nerve growth factor receptor. Of particular interest are membrane bound proteins that have type II transmembrane domains.
Membrane-bound proteins and receptor molecules have various industrial applications, including as pharmaceutical and diagnostic agents. Receptor immunoadhesins, for instance, can be employed as therapeutic agents to block receptor-ligand interaction. The membrane-bound proteins can also be employed for screening of potential peptide or small molecule inhibitors of the relevant receptor/ligand interaction.
Efforts are thus being undertaken by both industry and academia to identify new, native proteins, particularly membrane bound proteins including type II transmembrane bound proteins. Many efforts are focused on the screening of mammalian recombinant DNA libraries to identify the coding sequences for novel receptor proteins. The results of such efforts are provided herein.
81. PRO1083
Of particular interest are membrane bound proteins that belong to the seven transmembrane (7TM) receptor superfamily. Examples of these receptors include G-protein coupled receptors such as ion receptors. Another example of a 7TM receptor superfamily member is described in Osterhoff, et al., DNA Cell Biol., 16(4):379–389 (1997).
Membrane-bound proteins and receptor molecules have various industrial applications, including as pharmaceutical and diagnostic agents. Receptor immunoadhesins, for instance, can be employed as therapeutic agents to block receptor-ligand interaction. The membrane-bound proteins can also be employed for screening of potential peptide or small molecule inhibitors of the relevant receptor/ligand interaction.
Efforts are being undertaken by both industry and academia to identify new, native receptor proteins. Many efforts are focused on the screening of mammalian recombinant DNA libraries to identify the coding sequences for novel receptor proteins. The results of such efforts are presented herein.
82. PRO200
Polypeptides involved in survival, proliferation and/or differentiation of cells are of interest. Polypeptides known to be involved in the survival, proliferation and/or differentiation of cells include VEGF and members of the bone morphogenetic protein family. Therefore, novel polypeptides which are related to either VEGF or the bone morphogenetic protein are of interest.
The heparin-binding endothelial cell-growth factor, VEGF, was identified and purified from media conditioned by bovine pituitary follicular or folliculo-stellate cells over several years ago. See Ferrara et al., Biophys. Res. Comm. 161, 851 (1989). VEGF is a naturally occurring compound that is produced in follicular or folliculo-stellate cells (FC), a morphologically well characterized population of granular cells. The PC are stellate cells that send cytoplasmic processes between secretory cells.
VEGF is expressed in a variety of tissues as multiple homodimeric forms (121, 165, 189 and 206 amino acids per monomer) resulting from alternative RNA splicing. VEGF121 is a soluble mitogen that does not bind heparin; the longer forms of VEGF bind heparin with progressively higher affinity. The heparin-binding forms of VEGF can be cleaved in the carboxy terminus by plasmin to release (a) diffusible form(s) of VEGF. Amino acid sequencing of the carboxy terminal peptide identified after plasmin cleavage is Arg110-Ala111. Amino terminal “core” protein, VEGF(1–110) isolated as a homodimer, binds neutralizing monoclonal antibodies (4.6.1 and 2E3) and soluble forms of FMS-like tyrosine kinase (FLT-1), kinase domain region (KDR) and fetal liver kinase (FLK) receptors with similar affinity compared to the intact VEGF165 homodimer.
As noted, VEGF contains two domains that are responsible respectively for binding to the KDR and FLT-1 receptors. These receptors exist only on endothelial (vascular) cells. As cells become depleted in oxygen, because of trauma and the like, VEGF production increases in such cells which then bind to the respective receptors in order to signal ultimate biological effect. The signal then increases vascular permeability and the cells divide and expand to form new vascular pathways—vasculogenesis and angiogenesis.
Thus, VEGF is useful for treating conditions in which a selected action on the vascular endothelial cells, in the absence of excessive tissue growth, is important, for example, diabetic ulcers and vascular injuries resulting from trauma such as subcutaneous wounds. Being a vascular (artery and venus) endothelial cell growth factor, VEGF restores cells that are damaged, a process referred to as vasculogenesis, and stimulates the formulation of new vessels, a process referred to as angiogenesis.
VEGF would also find use in the restoration of vasculature after a myocardial infarct, as well as other uses that can be deduced. In this regard, inhibitors of VEGF are sometimes desirable, particularly to mitigate processes such as angiogenesis and vasculogenesis in cancerous cells.
Regarding the bone morphogenetic protein family, members of this family have been reported as being involved in the differentiation of cartilage and the promotion of vascularization and osteoinduction in preformed hydroxyapatite. Zou, et al., Genes Dev. (U.S.), 11(17):2191 (1997); Levine, et al., Ann. Plast. Surg., 39(2):158 (1997). A number of related bone morphogenetic proteins have been identified, all members of the bone morphogenetic protein (BMP) family. Bone morphogenetic native and mutant proteins, nucleic acids encoding therefor, related compounds including receptors, host cells and uses are further described in at least: U.S. Pat. Nos. 5,670,338; 5,454,419; 5,661,007; 5,637,480; 5,631,142; 5,166,058; 5,620,867; 5,543,394; 4,877,864; 5,013,649; 55,106,748; and 5,399,677. Of particular interest are proteins having homology with bone morphogenetic protein 1, a procollagen C-proteinase that plays key roles in regulating matrix deposition.
The present invention is predicated upon research intended to identify novel polypeptides which are related to VEGF and the BMP family, and in particular, polypeptides which have a role in the survival, proliferation and/or differentiation of cells. While the novel polypeptides are not expected to have biological activity identical to the known polypeptides to which they have homology, the known polypeptide biological activities can be used to determine the relative biological activities of the novel polypeptides. In particular, the novel polypeptides described herein can be used in assays which are intended to determine the ability of a polypeptide to induce survival, proliferation or differentiation of cells. In turn, the results of these assays can be used accordingly, for diagnostic and therapeutic purposes. The results of such research is the subject of the present invention.
83. PRO285 and PRO286
The cloning of the Toll gene of Drosophila, a maternal effect gene that plays a central role in the establishment of the embryonic dorsal-ventral pattern, has been reported by Hashimoto et al., Cell 52, 269–279 (1988). The Drosophila Toll gene encodes an integral membrane protein with an extracytoplasmic domain of 803 amino acids and a cytoplasmic domain of 269 amino acids. The extracytoplasmic domain has a potential membrane-spanning segment, and contains multiple copies of a leucine-rich segment, a structural motif found in many transmembrane proteins. The Toll protein controls dorsal-ventral patterning in Drosophila embryos and activates the transcription factor Dorsal upon binding to its ligand Spatzle. (Morisato and Anderson, Cell 76, 677–688 (1994).) In adult Drosophila, the Toll/Dorsal signaling pathway participates in the anti-fungal immune response. (Lenaitre et al., Cell 86, 973–983 (1996).)
A human homologue of the Drosophila Toll protein has been described by Medzhitov et al., Nature 388, 394–397 (1997). This human Toll, just as Drosophila Toll, is a type I transmembrane protein, with an extracellular domain consisting of 21 tandemly repeated leucine-rich motifs (leucine-rich region—LRR), separated by a non-LRR region, and a cytoplasmic domain homologous to the cytoplasmic domain of the human interleukin-1 (IL-1) receptor. A constitutively active mutant of the human Toll transfected into human cell lines was shown to be able to induce the activation of NF-κB and the expression of NF-κB controlled genes for the inflammatory cytokines IL-1, IL6 and IL-8, as well as the expression of the constimulatory molecule B7.1, which is required for the activation of native T cells. It has been suggested that Toll functions in vertebrates as a non-clonal receptor of the immune system, which can induce signals for activating both an innate and an adaptive immune response in vertebrates. The human Toll gene reported by Medzhitov et al., supra was most strongly expressed in spleen and peripheral blood leukocytes (PBL), and the authors suggested that its expression in other tissues may be due to the presence of macrophages and dendritic cells, in which it could act as an early-warning system for infection. The public GenBank database contains the following Toll sequences: Toll1 (DNAX#HSU88540-1, which is identical with the random sequenced full-length cDNA#HUMRSC786-1); Toll2 (DNAX#HSU88878-1); Toll3 (DNAX#HSU88879-1); and Toll4 (DNAX#HSU88880-1, which is identical with the DNA sequence reported by Medzhitov et al., supra). A partial Toll sequence (Toll5) is available from GenBank under DNAX#HSU88881-1.
Further human homologues of the Drosophila Toll protein, designated as Toll-like receptors (huTLRs1–5) were recently cloned and shown to mirror the topographic structure of the Drosophila counterpart (Rock et al., Proc. Natl. Acad. Sci. USA 95, 588–593 [1998]). Overexpression of a constitutively active mutant of one human TLR (Toll-protein homologue—Medzhitov et al., supra; TLR4 —Rock et al., supra) leads to the activation of NF-κB and induction of the inflammatory cytokines and constimulatory molecules. Medzhitov et al., supra.
84. PRO213–1, PRO1330 and PRO1449
Cancer is characterized by the increase in the number of abnormal, or neoplastic, cells derived from a normal tissue which proliferate to form a tumor mass, the invasion of adjacent tissues by these neoplastic tumor cells, and the generation of malignant cells which eventually spread via the blood or lymphatic system to regional lymph nodes and to distant sites (metastasis). In a cancerous state a cell proliferates under conditions in which normal cells would not grow. Cancer manifests itself in a wide variety of forms, characterized by different degrees of invasiveness and aggressiveness.
Alteration of gene expression is intimately related to the uncontrolled cell growth and de-differentiation which are a common feature of all cancers. The genomes of certain well studied tumors have been found to show decreased expression of recessive genes, usually referred to as tumor suppression genes, which would normally function to prevent malignant cell growth, and/or overexpression of certain dominant genes, such as oncogenes, that act to promote malignant growth. Each of these genetic changes appears to be responsible for importing some of the traits that, in aggregate, represent the full neoplastic phenotype (Hunter, Cell 64, 1129 [1991]; Bishop, Cell 64, 235–248 [1991]).
A well known mechanism of gene (e.g. oncogene) overexpression in cancer cells is gene amplification. This is a process where in the chromosome of the ancestral cell multiple copies of a particular gene are produced. The process involves unscheduled replication of the region of chromosome comprising the gene, followed by recombination of the replicated segments back into the chromosome (Alitalo et al., Adv. Cancer Res. 47, 235–281 [1986]). It is believed that the overexpression of the gene parallels gene amplification, i.e. is proportionate to the number of copies made.
Proto-oncogenes that encode growth factors and growth factor receptors have been identified to play important roles in the pathogenesis of various human malignancies, including breast cancer. For example, it has been found that the human ErbB2 gene (erbB2, also known as her2, or c-erbB-2), which encodes a 185-kd transmembrane glycoprotein receptor (p185HER2; HER2) related to the epidermal growth factor receptor (EGFR), is overexpressed in about 25% to 30% of human breast cancer (Slamon et al., Science 235:177–182 [1987]; Slamon et al., Science 244:707–712 [1989]).
It has been reported that gene amplification of a protooncogene is an event typically involved in the more malignant forms of cancer, and could act as a predictor of clinical outcome (Schwab et al., Genes Chromosomes Cancer 1, 181–193 [1990]; Alitalo et al., supra). Thus, erbB2 overexpression is commonly regarded as a predictor of a poor prognosis, especially in patients with primary disease that involves axillary lymph nodes (Slamon et al., [1987] and [1989], supra; Ravdin and Chamness, Gene 159:19–27 [1995]; and Hynes and Stem, Biochem Biophys Acta 1198: 165–184 [1994]), and has been linked to sensitivity and/or resistance to hormone therapy and chemotherapeutic regimens, including CMF (cyclophosphamide, methotrexate, and fluoruracil) and anthracyclines (Baselga et al., Oncology 11 (3 Suppl 1): 43–48 [1997]). However, despite the association of erbB2 overexpression with poor prognosis, the odds of HER2-positive patients responding clinically to treatment with taxanes were greater than three times those of HER2-negative patients (Ibid). A recombinant humanized anti-ErbB2 (anti-HER2) monoclonal antibody (a humanized version of the murine anti-ErbB2 antibody 4D5, referred to as rhuMAb HER2 or Herceptin 7δ) has been clinically active in patients with ErbB2-overexpressing metastatic breast cancers that had received extensive prior anticancer therapy. (Baselga et al., J. Clin. Oncol. 14:737–744 [1996]).
The protein Notch and its homologues are key regulatory receptors in determining the cell fate in various development processes. The protein Notch-4, also known as int-3 oncogene, was originally identified as a frequent target in mouse mammary tumor virus (MMVS). Notch-4 is believed to be a transgene which affects the differentiation capacity of stem cells and leads to neoplastic proliferation in epithelial cells. Shirayoshi et al., Genes Cells 2(3): 213–224 (1997). During embryogenesis, the expression of Notch-4 was detected in endothelial cells of blood vessels forming tissues such as the dorsal aorta, intersegmental vessels, yolk sac vessels, cephalic vessels, heart, vessels in branchial arches, and capillary plexuses. Notch-4 expression in these tissues was also associated with flk-1, the major regulatory gene of vasculogenesis and angiogenesis. Notch-4 is also upregulated in vitro during the differentiation of endothelial stem cell. The endothelial cell specific expression pattern of Notch-4, as well as its structural similarity to Notch suggest that Notch-4 is an endothelial cell specific homologue of Notch and that it may play a role in vaculogenesis and angiogenesis.
85. PRO298
Efforts are being undertaken by both industry and academia to identify new, native receptor proteins. Many efforts are focused on the screening of mammalian recombinant DNA libraries to identify the coding sequences for novel receptor proteins. We herein describe the identification and characterization of novel transmembrane polypeptides, designated herein as PRO298 polypeptides.
86. PRO337
Neuronal development in higher vertebrates is characterized by processes that must successfully navigate distinct cellular environment en route to their synaptic targets. The result is a functionally precise formation of neural circuits. The precision is believed to result form mechanisms that regulate growth cone pathfinding and target recognition, followed by latter refinement and remodeling of such projections by events that require neuronal activity, Goodman and Shatz, Cell/Neuron [Suppl.] 72(10): 77–98 (1993). It is further evident that different neurons extend nerve fibers that are biochemically distinct and rely on specific guidance cues provided by cell-cell, cell-matrix, and chemotrophic interactions to reach their appropriate synaptic targets, Goodman et al., supra.
One particular means by which diversity of the neuronal cell surface may be generated is through differential expression of cell surface proteins referred to as cell adhesion molecules (CAMs). Neuronally expressed CAMs have been implicated indiverse developmental processes, including migration of neurons along radial glial cells, providing permissive or repulsive substrates for neurite extension, and in promoting the selective fasciculation of axons in projectional pathways. Jessel, Neuron 1: 3–13 (1988); Edelman and Crossin, Annu. Rev. Biochem. 60: 155–190 (1991). Interactions between CAMs present on the growth cone membrane and molecules on opposing cell membranes or in the extracellular matrix are thought to provide the specific guidance cues that direct nerve fiber outgrowth along appropriate projectional pathways. Such interactions are likely to result in the activation of various second messenger systems within the growth cone that regulate neurite outgrowth. Doherty and Walsh, Curr. Opin Neurobiol. 2: 595–601 (1992).
In higher vertebrates, most neural CAMs have been found to be members of three major structural families of proteins: the integrins, the cadherins, and the immunoglobulin gene superfamily (IgSF). Jessel, supra.; Takeichi, Annu. Rev. Biochem. 59: 237–252 (1990); Reichardt and Tomaselli, Annu. Rev. Neurosci. 14: 531–570 (1991). Cell adhesion molecules of the IgSF (or Ig-CAMs), in particular, constitute a large family of proteins frequently implicated in neural cell interactions and nerve fiber outgrowth during development, Salzer and Colman, Dev. Neurosci. 11: 377–390 (1989); Brümmendorf and Rathjen, J. Neurochem. 61: 1207–1219 (1993). However, the majority of mammalian Ig-CAMs appear to be too widely expressed to specify navigational pathways or synaptic targets suggesting that other CAMs, yet to be identified, have role in these more selective interactions of neurons.
Many of the known neural Ig-CAMs have been found to be attached to the plasma membrane via a glycosylphosphatidylinositol (GPI) anchor. Additionally, many studies have implicated GPI-anchored proteins in providing specific guidance cues during the outgrowth on neurons in specific pathways. In studies of the grasshopper nervous system, treatment of embryos with phosphatidylinositol-specific phopholipase C (PIPLC), which selectively removes GPI-anchored proteins from the surfaces of cells, resulted in misdirection and faulty navigation among subsets of pioneering growth cones, as well as inhibited migratory patterns of a subset of early neurons, Chang et al., Devel. 114: 507–519 (1992). The projection of retinal fibers to the optic tectum appears to depend, in part, on a 33 kDa GPI-anchored protein, however, the precise nature of this protein is unknown. Stahl et al., Neuron 5: 735–743 (1990).
The expression of various GPI-anchored proteins has been characterized amongst the different populations of primary rat neurons amongst dorsal root ganglion, sympathetic neurons of the cervical ganglion, sympathetic neurons of the superior cervical ganglion, and cerebellar granule neurons. Rosen et al., J. Cell Biol. 117: 617–627 (1992). In contrast to the similar pattern of total membrane protein expression by these different types of neurons, striking differences were observed in the expression of GPI-anchored proteins between these neurons. Recently, a 65 kDa protein band known as neurotrimin was discovered and found to be differentially expressed by primary neurons (Rosen et al., supra), and restricted to the nervous system and found to be the most abundant and earliest expressed of the GPI-anchored species in the CNS. Struyk et al., J. Neuroscience 15(3): 2141–2156 (1995). The discovery of neutrotrimin has further lead to the identification of a family of IgSF members, each containing three Ig-like domains that share significant amino acid identity, now termed IgLON. Struyk et al., supra; Pimenta et al., Gene 170(2): 189–95 (1996).
Additional members of the IgLON subfamily include opiate binding cell adhesion molecule (OBCAM), Schofield et al., EMBO J. 8: 489–495 (1989); limbic associated membrane protein (LAMP), Pimenta et al., supra; CEPU-1; GP55, Wilson et al., J. Cell Sci. 109: 3129–3138 (1996); Eur. J. Neurosci. 9(2):334–41 (1997); and AvGp50, Hancox et al., Brain Res. Mol. Brain Res. 44(2): 273–85 (1997).
While the expression of neurotrimin appears to be widespread, it does appear to correlated with the development of several neural circuits. For example, between E18 and P10, neurotimin mRNA expression within the forebrain is maintained at high levels in neurons of the developing thalamus, cortical subplate, and cortex, particularly laminae V and VI (with less intense expression in II, II, and IV, and minimal expression in lamina I). Cortical subplate neurons may provide an early, temporary scaffold for the ingrowing thalamic afferents en route to their final synaptic targets in the cortex. Allendoerfer and Shatz, Annu. Rev. Neurosci. 17: 185–218 (1994). Conversely, subplate neurons have been suggested to be required for cortical neurons from layer V to select VI to grow into the thalamus, and neurons from layer V to select their targets in the colliculus, pons, and spinal cord (McConnell et al., J. Neurosci. 14: 1892–1907 (1994). The high level expression of neurotrimin in many of these projections suggests that it could be involved in their development.
In the hindbrain, high levels of neurotrimin message expression were observed within the pontine nucleus and by the internal granule cells and Purkinje cells of the cerebellum. The pontine nucleus received afferent input from a variety of sources including corticopontine fibers of layer V, and is a major source of afferent input, via mossy fibers, to the granule cells which, in turn, are a major source of afferent input via parallel fibers to Purkinje cells. [Palay and Chan-Palay, The cerebellar cortex: cytology and organization. New York: Springer (1974]. High level expression of neurotrimin these neurons again suggests potential involvement in the establishment of these circuits.
Neurotrimin also exhibits a graded expression pattern in the early postnatal striatum. Increased neurotrimin expression is found overlying the dorsolateral striatum of the rat, while lesser hybridization intensity is seen overlying the ventromedial striatum. Struyk et al., supra. This region of higher neurotrain hybridization intensity does not correspond to a cytoarchitecturally differentiable region, rather it corresponds to the primary area of afferent input from layer VI of the contralateral sensorimotor cortex (Gerfen, Nature 311: 461–464 (1984); Donoghue and Herkenham, Brain Res. 365: 397–403 (1986)). The ventromedial striatum, by contrast, receives the majority of its afferent input from the perirhinal and association cortex. It is noteworthy that a complementary graded pattern of LAMP expression, has been observed within the striatium, with highest expression in ventromedial regions, and lowest expression dorsolaterally. Levitt, Science 223: 299–301 (1985); Chesselet et al., Neuroscience 40: 725–733 (1991).
87. PRO403
Type II transmembrane proteins, also known as single pass transmembrane proteins have an N-terminal portion lodged in the cytoplasm while the C-terminal portion is exposed to the extracellular domain.
Endothelin is a family of vasoconstrictor peptides about which much activity has been focused to better understand its basic pharmacological, biochemical and molecular biological features, including the presence and structure of isopeptides and their genes (endothelin-1, -2 and û3), regulation of gene expression, intracellular processing, specific endothelin converting enzymes (ECE), receptor subtypes (ET-A and ET-B), intracellular signal transduction following receptor activation, etc.
The endothelin (ET) family of peptides have potent vascular, cardiac and renal actions which may be of pathophysiological importance in many human disease states. ET-1 is expressed as an inactive 212 amino acid prepropeptide. The prepropeptide is first cleaved at Arg52-Cys53 and Arg92-Ala93 and then the carboxy terminal Lys91 and Arg92 are trimmed from the protein to generate the propeptide big ET-1.
Endothelin is generated from inactive intermediates, the big endothelins, by a unique processing event catalyzed by the zinc metalloprotease, endothelin converting enzyme (ECE). ECE was recently cloned, and its structure was shown to be a single pass transmembrane protein with a short intracellular N-terminal and a long extracellular C-terminal that contains the catalytic domain and numerous N-glycosylation sites. ECEs cleave the endothelin propeptide between Trp73 and Val74 producing the active peptide, ET, which appears to function as a local rather than a circulating hormone (Rubanyi, G. M. & Polokoff, M. A., Pharmachological Reviews 46: 325–415 (1994). Thus ECE activity is a potential site of regulation of endothelin production and a possible target for therapeutic intervention in the endothelin system. By blocking ECE activity, it is possible stop the production of ET-1 by inhibiting the conversion of the relatively inactive precursor, big ET-1, to the physiologically active form.
Endothelins may play roles in the pathophysiology of a number of disease states including: 1) cardiovascular diseases (vasospasm, hypertension, myocardial ischemia; reperfusion injury and acute myochardial infarction, stroke (cerebral ischemia), congestive heart failure, shock, atherosclerosis, vascular thickening); 2) kidney disease (acute and chronic renal failure, glomerulonephritis, cirrhosis); 3) lung disease (bronchial asthma, pulmonary hypertension); 4) gastrointestinal disorders (gastric ulcer, inflammatory bowel diseases); 5) reproductive disorders (premature labor, dysmenorhea, preeclampsia) and 6) carcinogenesis. Rubanyi & Polokoff, supra.